Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Prepared in cooperation with the New York State Department of Environmental Conservation

Open-File Report 2019–1005

U.S. Department of the Interior U.S. Geological Survey Cover. View of the landscape in the Delaware River Basin. Photograph by Elizabeth Nystrom, U.S. Geological Survey. Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

By Tia-Marie Scott, Elizabeth A. Nystrom, and James E. Reddy

Prepared in cooperation with the New York State Department of Environmental Conservation

Open-File Report 2019–1005

U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior DAVID BERNHARDT, Secretary U.S. Geological Survey James F. Reilly II, Director

U.S. Geological Survey, Reston, Virginia: 2019

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Suggested citation: Scott, T.-M., Nystrom, E.A., and Reddy, J.E., 2019, Groundwater quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015: U.S. Geological Survey Open-File Report 2019–1005, 42 p., 2 app., https://doi.org/10.3133/ofr20191005.

ISSN 2331-1258 (online) iii

Acknowledgments

The authors extend thanks and appreciation to all well owners who gave permission to sample their wells. Thanks are also extended to our contacts at the New York State (NYS) Department of Environmental Conservation, NYS Department of Health, county departments of health, and to all of the public water supply personnel who provided information and help with this study. Additionally, the authors would like to extend thanks and appreciation to U.S. Geological Survey personnel James Tucci, Daniel Edwards, and Benjamin Fisher for their work collecting the samples.

Contents

Abstract...... 1 Introduction...... 1 Objective and Approach...... 2 Purpose and Scope...... 3 Hydrogeologic Setting...... 3 Delaware River Basin...... 3 Genesee River Basin...... 3 St. Lawrence River Basin...... 8 Methods of Investigation...... 14 Well Selection...... 14 Sampling Methods...... 14 Analytical Methods...... 15 Quality-Control Samples...... 18 Groundwater Quality...... 19 Physiochemical Properties...... 19 Dissolved Gases...... 23 Major Ions and Dissolved Solids...... 24 Nutrients and Total Organic Carbon...... 26 Trace Elements...... 28 Pesticides...... 31 Volatile Organic Compounds...... 31 Radionuclides...... 32 Bacteria...... 32 Comparison of Results From Wells Sampled in 2005–6, 2010, and 2015...... 34 Summary...... 35 References Cited...... 36 Appendix 1. Results of Water-Sample Analyses, 2015...... 42 Appendix 2. Results of Water-Sample Analyses, 2005–6, 2010, and 2015...... 42

Figures

1. Map showing topography and geography of the Delaware River Basin, New York...... 4 2. Map showing generalized bedrock geology of the Delaware River Basin, New York, and locations of wells sampled in 2015...... 5 3. Map showing generalized surficial geology of the Delaware River Basin, New York, and locations of wells sampled in 2015...... 6 4. Map showing topography and geography of the Genesee River Basin, New York...... 7 5. Map showing generalized bedrock geology of the Genesee River Basin, New York, and locations of wells sampled in 2015...... 9 6. Map showing generalized surficial geology of the Genesee River Basin, New York, and locations of wells sampled in 2015...... 10 7. Map showing topography and geography of the St. Lawrence River Basin, New York...... 11 8. Map showing generalized bedrock geology of the St. Lawrence River Basin, New York, and locations of wells sampled in 2015...... 12 9. Map showing generalized surficial geology of the St. Lawrence River Basin, New York, and locations of wells sampled in 2015...... 13 vi

Tables

1. Previous groundwater-quality studies and reports of the rotating-basin groundwater monitoring program in New York...... 2 2. Description of wells from which water samples were collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 16 3. Summary of 46 wells from which water samples were collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 18 4. Constituents that exceeded primary, secondary, and (or) proposed drinking-water standards in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 20 5. Summary statistics for physiochemical properties of and dissolved gases in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 22 6. Drinking-water standards for physiochemical properties and dissolved gases and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 23 7. Summary statistics for concentrations of major ions, hardness, alkalinity, and dissolved solids in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 25 8. Drinking-water standards for concentrations of major ions and dissolved solids and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 26 9. Summary statistics for concentrations of nutrients in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 27 10. Drinking-water standards for concentrations of nutrients and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 28 11. Summary statistics for concentrations of trace elements in groundwater collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 29 12. Drinking-water standards for concentrations of trace elements and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 30 13. Summary statistics for activities of radionuclides in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 33 14. Drinking-water standards for activities of radionuclides and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015...... 34 vii

Conversion Factors

U.S. customary units to International System of Units

Multiply By To obtain inch (in.) 25,400 micrometer (µm) foot (ft) 0.3048 meter (m) mile (mi) 1.609 kilometer (km) square mile (mi2) 259.0 hectare (ha) square mile (mi2) 2.590 square kilometer (km2) gallon (gal) 3.785 liter (L) gallon per minute (gal/min) 0.06309 liter per second (L/s) inch per year (in/yr) 25.4 millimeter per year (mm/yr) picocurie per liter (pCi/L) 0.037 becquerel per liter (Bq/L)

Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as °F = (1.8 × °C) + 32.

Datum

Vertical coordinate information is referenced to the North American Vertical Datum of 1988 (NAVD 88). Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83). Elevation, as used in this report, refers to distance above the vertical datum.

Supplemental Information

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C). Concentrations of chemical constituents in water are given either in milligrams per liter (mg/L), micrograms per liter (µg/L), or nanograms per liter (ng/L). Activities for radioactive constituents in water are given in picocuries per liter (pCi/L). Concentrations of bacteria in water are given in colony-forming units per 100 milliliters (CFU/100 mL); heterotrophic plate counts are in colony-forming units per milliliter (CFU/mL).

Color is reported in platinum-cobalt (Pt-Co) units. viii

Abbreviations and Symbols

> greater than < less than AMCL alternative maximum contaminant level bls below land surface

CaCO3 calcium carbonate CFU colony-forming units CIAT 2-chloro-4-isopropylamino-6-amino-s-triazine E. coli Escherichia coli EPA U.S. Environmental Protection Agency GC–MS gas chromatography-mass spectrometry gross-α gross-alpha gross-β gross-beta ICP–AES inductively coupled plasma-atomic emission spectrometry LRL laboratory reporting level MCL maximum contaminant level N nitrogen NWQL USGS National Water Quality Laboratory NYSDEC New York State Department of Environmental Conservation NYSDOH New York State Department of Health P phosphorus SDWS secondary drinking-water standard THM trihalomethane USGS U.S. Geological Survey VOC volatile organic compound Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

By Tia-Marie Scott, Elizabeth A. Nystrom, and James E. Reddy

Abstract 21 wells sampled in the St. Lawrence River Basin, 7 are completed in sand and gravel, and 14 are completed in bedrock. The U.S. Geological Survey, in cooperation with the Groundwater in the St. Lawrence River Basin was generally of New York State Department of Environmental Conservation, good quality, although properties and concentrations of some collected groundwater samples from 5 production wells and constituents—pH, chloride, sodium, dissolved solids, iron, 5 domestic wells in the Delaware River Basin, 8 production manganese, sulfate, nitrate, radon-222, total coliform bacteria, wells and 7 domestic wells in the Genesee River Basin, and fecal coliform bacteria, and Escherichia coli bacteria—some- 1 municipal well, 7 production wells, and 13 domestic wells in times equaled or exceeded primary, secondary, or proposed the St. Lawrence River Basin in New York. All samples were drinking-water standards. The constituent most frequently collected from May through November 2015 in an effort to detected in concentrations exceeding drinking-water standards characterize groundwater quality in these basins. The samples (14 of 21 samples) was radon-222. were collected and processed by using standard U.S. Geo- logical Survey procedures and were analyzed for 148 physiochemical properties and constituents, including dissolved Introduction gases, major ions, nutrients, trace elements, pesticides, volatile organic compounds, radionuclides, and indicator bacteria. Groundwater is used as a source of drinking water by The Delaware River Basin study area covers 2,360 square approximately one-quarter of the population of New York miles (mi2) in southeastern New York. Of the 10 wells sam- State, or 4.5 million people (U.S. Census Bureau, 2016) pled in the Delaware River Basin, 3 are completed in sand and (Kenny and others, 2009). In 2002, the U.S. Geological Sur- gravel, and 7 are completed in bedrock. Groundwater in the vey (USGS), in cooperation with the New York State Depart- Delaware River Basin was generally of good quality, although ment of Environmental Conservation (NYSDEC), developed properties and concentrations of some constituents—pH, iron, a program to evaluate groundwater quality throughout the manganese, aluminum, radon-222, and total coliform bacteria—sometimes equaled or exceeded primary, secondary, or major river basins in Upstate New York on a rotating basis. proposed drinking-water standards. The constituent most fre- The program parallels the NYSDEC Rotating Integrated Basin quently detected in concentrations exceeding drinking-water Study program (https://www.dec.ny.gov/chemical/30951. standards (10 of 10 samples) was radon-222. html), which evaluates surface-water quality on a 5-year The Genesee River Basin study area includes the entire cycle by sampling in 2 or 3 of the 14 major river basins in 2,439 mi2 of the basin in western New York. Of the 15 wells the State each year. This program also supports NYSDEC’s sampled in the Genesee River Basin, 6 are completed in sand responsibilities under Section 305(b) of the Clean Water Act and gravel, and 9 are completed in bedrock. Groundwater Amendments of 1977 (Public Law 95–95, 91 Stat. 685) to in the Genesee River Basin was generally of good quality, report on the chemical quality of groundwater within New although properties and concentrations of some constituents— York (U.S. Environmental Protection Agency, 1997). The chloride, sodium, dissolved solids, iron, manganese, alumi- groundwater-quality program began with a pilot study in the num, arsenic, radon-222, methane, total coliform bacteria, Mohawk River Basin in 2002 and still continues throughout fecal coliform bacteria, and Escherichia coli bacteria—some- Upstate New York, that part of New York State north of New times equaled or exceeded primary, secondary, or proposed York City (table 1). Sampling completed in 2008 represents drinking-water standards. The constituent most frequently the conclusion of the first round of groundwater-quality detected in concentrations exceeding drinking-water standards sampling throughout Upstate New York. Groundwater-quality (12 of 15 samples) was radon-222. sampling was conducted in 2015 in the Delaware, Genesee, The St. Lawrence River Basin study area includes the and St. Lawrence River Basins, representing the third round of entire 5,650 mi2 of the basin in northeastern New York. Of the groundwater-quality sampling for this program. 2 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 1. Previous groundwater-quality studies and reports of the rotating-basin groundwater monitoring program in New York.

[Bold listing indicates the previous groundwater-quality studies in the Delaware River Basin, Genesee River Basin, and St. Lawrence River Basin]

Study area Year Report Reference Mohawk River Basin 2002 Water-Data Report NY–02–1 Butch and others, 2003 Chemung River Basin 2003 Open-File Report 2004–1329 Hetcher-Aguila, 2005 Lake Champlain Basin 2004 Open-File Report 2006–1088 Nystrom, 2006 Susquehanna River Basin 2004 Open-File Report 2006–1161 Hetcher-Aguila and Eckhardt, 2006 Delaware River Basin 2005 Open-File Report 2007–1098 Nystrom, 2007a Genesee River Basin 2005 Open-File Report 2007–1093 Eckhardt and others, 2007 St. Lawrence River Basin 2005 Open-File Report 2007–1066 Nystrom, 2007b Mohawk River Basin 2006 Open-File Report 2008–1086 Nystrom, 2008 Western New York 2006 Open-File Report 2008–1140 Eckhardt and others, 2008 Central New York 2007 Open-File Report 2009–1257 Eckhardt and others, 2009 Upper Hudson River Basin 2007 Open-File Report 2009–1240 Nystrom, 2009 Chemung River Basin 2008 Open-File Report 2011–1112 Risen and Reddy, 2011a Eastern Lake Ontario Basin 2008 Open-File Report 2011–1074 Risen and Reddy, 2011b Lower Hudson River Basin 2008 Open-File Report 2010–1197 Nystrom, 2010 Lake Champlain Basin 2009 Open-File Report 2011–1180 Nystrom, 2011 Susquehanna River Basin 2009 Open-File Report 2012–1045 Reddy and Risen, 2012 Delaware River Basin 2010 Open-File Report 2011–1320 Nystrom, 2012 Genesee River Basin 2010 Open-File Report 2012–1135 Reddy, 2012 St. Lawrence River Basin 2010 Open-File Report 2011–1320 Nystrom, 2012 Mohawk River Basin 2011 Open-File Report 2013–1021 Nystrom and Scott, 2013 Western New York 2011 Open-File Report 2013–1095 Reddy, 2013 Central New York 2012 Open-File Report 2014–1226 Reddy, 2014 Upper Hudson River Basin 2012 Open-File Report 2014–1084 Scott and Nystrom, 2014 Chemung River Basin 2013 Open-File Report 2015–1168 Scott and others, 2015 Eastern Lake Ontario Basin 2013 Open-File Report 2015–1168 Scott, and others, 2015 Lower Hudson River Basin 2013 Open-File Report 2015–1168 Scott, and others, 2015 Lake Champlain Basin 2014 Open-File Report 2016–1153 Scott, and others, 2016 Susquehanna River Basin 2014 Open-File Report 2016–1153 Scott, and others, 2016

Objective and Approach study cycles. Samples were analyzed for a broad suite of constituents, including physiochemical properties and concentra- The objective of the groundwater-quality monitoring tions of dissolved gases, major ions, nutrients, trace elements, program is to quantify and report on ambient groundwater pesticides, volatile organic compounds (VOCs), radionuclides, quality in bedrock and glacial-drift aquifers in Upstate New and indicator bacteria. The resulting dataset will be used to York. Consistent, standardized methods were used to col- establish a groundwater-quality baseline for New York State lect groundwater-quality samples from existing domestic that characterizes naturally occurring and ambient conditions and production wells equipped with permanently installed and to identify long-term trends. The data are made available pumps. Wells were selected to represent an approximately online through the USGS National Water Information System equal number of domestic and production wells, to represent (https://nwis.waterdata.usgs.gov/ny/nwis/qw; U.S. Geological an approximately equal number of bedrock and glacial-drift Survey, 2018) and published reports. wells, and to provide a representative geographic distribution Groundwater-quality samples were collected in the of samples with emphasis on areas of greatest groundwater Delaware, Genesee, and St. Lawrence River Basins in 2005–6, use. Approximately 20 percent of samples collected in 2015 2010, and 2015. Samples were collected in May through were collected from wells that had been sampled in previous November for the 2015 cycle of this study. Ten environmental Introduction 3 samples and 2 quality-assurance samples were collected in in New York include the West Branch Delaware River, East the Delaware River Basin. Fifteen environmental samples Branch Delaware River, Monguap River, and Neversink River. and 1 quality-assurance sample were collected in the Genesee Drinking water for New York City is diverted out of the basin River Basin. Twenty-one environmental samples and 1 qual- at three reservoirs: Cannonsville (on the West Branch Dela- ity-assurance sample were collected in the St. Lawrence River ware River), Pepacton (on the East Branch Delaware River), Basin. Two of the Delaware River Basin wells sampled in and Neversink (on the Neversink River). 2015 were also sampled in 2005–6 and 2010 (Nystrom, 2007a; The highest elevations in the Delaware River Basin study Nystrom 2012). Three of the Genesee River Basin wells were area are more than 4,000 feet (ft) above the North American also sampled in 2010 (Reddy, 2012). Five of the St. Lawrence Vertical Datum of 1988 (NAVD 88) along the eastern edge River Basin wells were also sampled in 2005–6 and 2010 of the basin, in the Catskill Mountains (fig. 1). The lowest (Nystrom, 2007b; Nystrom, 2012). elevations in the basin are at the Delaware River’s exit from New York State at Port Jervis (fig. 1) (about 420 ft above NAVD 88). Precipitation in the Delaware River valley lowland Purpose and Scope areas averages about 40 inches per year (in/yr), whereas precipitation in the cooler Catskill Mountains averages about This report presents the findings of the 2015 groundwa- 50 in/yr (Randall, 1996). The Delaware River Basin is mostly ter-quality study in the Delaware, Genesee, and St. Lawrence rural, with larger population centers in the southern part of River Basins. Ten samples from the Delaware River Basin, the basin at Port Jervis, Liberty, and Monticello (fig. 1). Land 15 samples from the Genesee River Basin, and 21 samples use in the basin is primarily forested, especially in the upland from the St. Lawrence River Basin were collected from areas, with urban and agriculture uses mainly in valleys and May through November 2015. This report (1) describes the other low-lying areas (Homer and others, 2015). hydrogeologic setting, the methods of site selection, wells Bedrock in the Delaware River Basin study area (fig. 2) is that were sampled, sample collection, and chemical analysis; mainly Middle to Upper Devonian sedimentary sandstone and (2) presents the analytical results; (3) presents comparisons of shale with a narrow band of carbonate rocks that runs parallel analytical results to drinking-water standards, and (4) pres- to the southern edge of the basin (Isachsen and others, 2000). ents comparisons of the results of this study with results for Bedrock wells in the study area produce small to moderate selected wells in the study areas that were sampled in 2005–6 yields of 10 to 100 gallons per minutes (gal/min) (Barksdale, and 2010 (Nystrom, 2007a, b; Nystrom, 2012; Reddy, 2012). 1970). The surficial material throughout the study area (fig. 3) was deposited primarily during the Pleistocene epoch Wiscon- Hydrogeologic Setting sinan glaciation, when glacial ice covered most of the northeastern United States (Isachsen and others, 2000). Till was The study areas described in this report cover more directly deposited by the glaciers over most of the study area; than 10,000 square miles (mi2), or 18 percent of New York alluvial, outwash, and ice-contact sand-and-gravel deposits are State, and represent a wide range of geologic, hydrologic, present mainly in the valleys (fig. 3). In the Delaware River and topographic settings, and land uses. Bedrock lithology is Basin, till generally has low yields of water, whereas the well- primarily shale and sandstone in the Delaware and Genesee sorted valley deposits form important aquifers in the basin River Basins; in the St. Lawrence River Basin, bedrock lithol- that may produce yields of 1,000 gal/min or more (Barksdale, ogy consists of complex mixtures of crystalline, metamorphic, 1970). The depths of sand-and-gravel wells sampled in the carbonate, and sandstone (Fisher and others, 1970). Surficial Delaware River Basin range from 42 to 120 ft below land material in the study areas mainly consists of glacial and allu- surface (bls); the depths of bedrock wells sampled range from vial deposits. 195 to 400 ft bls, and all are completed in shale and sandstone.

Delaware River Basin Genesee River Basin The Delaware River Basin encompasses approximately The Genesee River Basin encompasses 2,534 mi2, of 12,700 mi2 in New York, Pennsylvania, New Jersey, and which 95 mi2 is in Pennsylvania. The Genesee River Basin Delaware. This study addressed the 2,360 mi2 portion of the study area encompasses the 2,439 mi2 that is located in west- Delaware River Basin that lies within New York (fig. 1). The ern New York. The study area contains parts of nine counties, study area includes parts of eight counties, including most of including Genesee, Monroe, Livingston, Wyoming, Ontario, Delaware and Sullivan Counties, part of Broome, Orange, and Steuben, Allegany, Orleans, and Cattaraugus Counties (fig. 4). Ulster Counties, and small parts of Chenango, Greene, and Major tributaries to the Genesee River include Black Creek, Schoharie Counties (fig. 1). The West Branch Delaware River Oatka Creek, Conesus Creek, Honeoye Creek, Canaseraga forms the boundary between New York and Pennsylvania for Creek, Wiscoy Creek, Caneadea Creek, Van Campen Creek, 9 miles (mi) before joining with the East Branch to form the Dyke Creek, Silver Creek, and Silver Lake (fig. 4). Other main stem of the Delaware River, which forms the boundary major contributing tributaries in the Genesee River Basin for another 76 mi. Major tributaries to the Delaware River include Keshequa Creek, which is a tributary to Canaseraga 4 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

530 5 430 EPLANATION Elevationn feet above the North American ertical OTSEGO Datum of 1 4230 SCHOHARIE

CHENANGO

Study area boundary

West Branch Delaware River

GREENE

DELAWARE

Pepacton Cannonsville Reservoir Reservoir BROOME

NEW YORK 42 PENNSYLVANIA East Branch Delaware River Catskill Mountains

ULSTER

Neversink Reservoir

" Liberty Swan Lake

SULLIVAN

Monticello" Swinging Bridge Reservoir

Mangaup

Neversink River

4130 Delaware River ON River Lake VT Ontario NH " ORANGE NY Port Jervis Study area MA

NEW YORK NEW JERSEY CT

PA NJ Atlantic PENNSYLVANIA Ocean NEW JERSEY Base from U.S. Geological Survey digital data, 1983, 1:100,000 Hydrology from National Hydrography Dataset, 1:100,000 Universal Transverse Mercator projection Topography from National Elevation Dataset one 18

0 10 20 MLES

0 10 20 KLOMETERS

Figure 1. Topography and geography of the Delaware River Basin, New York. Introduction 5

530 5 430 EPLANATION Generalied bedrock geology Carbonate

OTSEGO Shale 4230 SCHOHARIE Shale and carbonates

Shale and sandstone CHENANGO ! Metamorphosed clastic D154 Crystalline

Study area boundary Wells sampled Bedrock well sampled and GREENE D 1 ! .S. Geological Survey well number (table 2) DELAWARE D1 D 26 Sand and gravel well sampled ! D 1 ! and .S. Geological Survey well number (table 2) BROOME D 26 ! D221 NEW YORK 42 PENNSYLVANIA S ULSTER ! S16 !S 12

S 54

SULLIVAN

4130

106 ! ORANGE

NEW YORK NEW JERSEY

PENNSYLVANIA NEW JERSEY

Base from U.S. Geological Survey digital data, 1983, 1:100,000 Geology modified from Fisher and others, 190 Universal Transverse Mercator projection one 18

0 10 20 MLES

0 10 20 KLOMETERS

Figure 2. Generalized bedrock geology of the Delaware River Basin, New York, and locations of wells sampled in 2015. 6 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

530 5 430 EPLANATION Generalied surficial geology Alluvium and outwash

OTSEGO Lacustrine sand, silt, and clay 4230 SCHOHARIE ce-contact deposits

Till CHENANGO ! Bedrock D154 Study area boundary Wells sampled D 1D 1 Bedrock well sampled and ! .S. Geological Survey GREENE well number (table 2) D 26D 26 Sand and gravel well sampled DELAWARE D1 and .S. Geological Survey ! D 1 ! well number (table 2)

BROOME D 26 ! D221 NEW YORK 42 PENNSYLVANIA S ULSTER ! S16 !S 12

S 54

SULLIVAN

4130

106 ! ORANGE

NEW YORK NEW JERSEY

PENNSYLVANIA NEW JERSEY

Base from U.S. Geological Survey digital data, 1983, 1:100,000 Geology modified from Cadwell, 1999 Universal Transverse Mercator projection one 18

0 10 20 MLES

0 10 20 KLOMETERS

Figure 3. Generalized surficial geology of the Delaware River Basin, New York, and locations of wells sampled in 2015. Introduction 7

830 8 30 EPLANATION Lake Elevationn feet above Erie Canal Ontario the North American ORLEANS NIAGARA ertical Datum of 1

" Rochester WAYNE MONROE Black Creek Erie Canal

43 GENESEE LeRoy Study area boundary "

Honeoye Creek

Genesee River " Avon Conesus Creek Canandaigua ERIE Lake Geneseo " ONTARIO Oatka Creek Conesus Lake LIVINGSTON Honeoye "Warsaw Lake Silver Creek WYOMING Silver Canaseraga Creek Lake Hemlock Lake Canadice Lake Mount Morris " YATES

East Koy Creek

Wiscoy Creek Keshequa Creek

4230 Dansville "

CaneadeaRushford Creek Lake

Black Creek CATTARAUGUS STEUBEN ALLEGANY

Van Campen Creek

Dyke Creek Wellsville Lake " Ontario Genesee River ON

42 NEW YORK Lake PENNSYLVANIA Erie NY Study area

OH PA NJ WV Base from U.S. Geological Survey digital data, 1983, 1:100,000 Hydrology from National Hydrography Dataset, 1:100,000 Universal Transverse Mercator projection Topography from National Elevation Dataset one 18

0 10 20 MLES

0 10 20 KLOMETERS

Figure 4. Topography and geography of the Genesee River Basin, New York. 8 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Creek, and East Koy Creek, which is a tributary to Wiscoy St. Lawrence River Basin include the Indian River, which is Creek. The Genesee River Basin contains four of the western a tributary to the Oswegatchie River. The St. Lawrence River Finger Lakes (Conesus, Hemlock, Canadice, and Honeoye Basin contains many freshwater lakes, ponds, and reservoirs, Lakes) and ultimately drains into Lake Ontario (fig. 4). the largest of which are Black Lake, Cranberry Lake, Raquette The highest elevations in the Genesee River Basin study Lake, Tupper Lake, and Long Lake. The St. Lawrence River area are more than 2,500 ft above NAVD 88 in the central and forms the outlet of the Great Lakes Basin, the largest fresh southern uplands (fig. 4). The lowest elevations in the study surface-water system in the world (Government of Canada and area are about 250 ft above NAVD 88, near where the Genesee U.S. Environmental Protection Agency, 1995), and ultimately River discharges into Lake Ontario (fig. 4). Precipitation in drains into the North Atlantic Ocean (fig. 7). the Genesee River Basin averages around 33 in/yr (Randall, The highest elevations in the St. Lawrence River Basin 1996). Land use is primarily forested and pasture in the steep study area are more than 4,000 ft above NAVD 88, along the uplands and narrow valleys that dominate the southern area southeastern edge of the basin in the Adirondack Mountains of the basin; row-crop and dairy agriculture is concentrated in (fig. 7). The lowest elevations in the study area are about the broad alluvial valley and the low rolling hills of the central 150 ft above NAVD 88, along the northern edge of the study basin; and the Rochester metropolitan area dominates the area in the St. Lawrence valley (fig. 7). Precipitation in the relatively flat plain of the northern basin (fig. 4). St. Lawrence River Basin study area (which only includes the Bedrock in the Genesee River Basin (fig. 5) mainly area located in New York State) averages around 35 in/yr in consists of flat-lying, interbedded sedimentary units of shale, the valley and lowlands and averages around 45 in/yr in the siltstone, sandstone, limestone, and dolostone of Silurian and uplands (Randall, 1996). Land use is primarily forested; how- Devonian age (Eckhardt and others, 2007). The surficial mate- ever, agricultural and urban areas in the study area are present rial throughout the Genesee River Basin was deposited primar- mainly in the St. Lawrence Valley (Homer and others, 2015). ily during the Pleistocene epoch Wisconsinan glaciation, when Population centers include Malone, Massena, Lisbon, Ogdens- glacial ice covered most of the northeastern United States burg, Potsdam, Canton, Gouverneur, Tupper Lake, and Blue (Isachsen and others, 2000). Till, which was directly depos- Mountain Lake (fig. 7). ited by the glaciers, discontinuously overlies bedrock in the Bedrock in the St. Lawrence River Basin (fig. 8) is uplands (fig. 6). Ice-contact and outwash sand and gravel and mainly crystalline, but two wide bands of carbonate and lacustrine sand, silt, and clay were deposited mainly in val- sandstone bedrock are present along the northern edge of leys. Recent alluvium overlies the glacial deposits in the flood the basin. As in the Delaware and Genesee River Basins, the plains of the larger streams and rivers (Coates, 1966; Randall, surficial material throughout the St. Lawrence River Basin 2001). In the Genesee River Basin, the most productive aqui- was deposited primarily during the Pleistocene epoch Wis- fers are the glacial and alluvial deposits of sand and gravel in consinan glaciation, when glacial ice covered most of the the valleys. Lacustrine and till deposits are relatively imper- northeastern United States (Isachsen and others, 2000). Till meable and yield little water to wells (Coates, 1966; Randall, was directly deposited by the glaciers, and ice-contact and 2001). In the Genesee River Basin, the depths of sand-and- outwash sand and gravel and lacustrine sand, silt, and clay gravel wells sampled range from 25 to 199 ft bls, and the were deposited mainly in valleys. Recent alluvium overlies the depths of bedrock wells sampled range from 50 to 262 ft bls. glacial deposits in the flood plains of the larger streams and The bedrock wells are completed in clastic (shale and sand- rivers (fig. 9) (Coates, 1966; Randall, 2001). Sand-and-gravel stone) or carbonate (limestone and dolostone) bedrock. deposits generally produce the highest yields in the St. Law- rence study area, but the sandstone and carbonate aquifers St. Lawrence River Basin along the northern edge of the basin in the St. Lawrence Val- ley (fig. 9) also produce moderate yields (Great Lakes Basin The St. Lawrence River Basin encompasses an area Commission, 1975). The crystalline bedrock in the Adiron- of nearly 300,000 mi2 in the United States and Canada. dack Mountains generally produces the lowest yields of the The St. Lawrence River Basin study area encompasses aquifers in the basin. Most wells in the St. Lawrence study 5,650 mi2 in northeastern New York and lies downstream area are completed in bedrock; production wells are completed from Lake Ontario (fig. 7). The study area contains parts of in sand-and-gravel deposits where they are present. In the eight counties, including St. Lawrence, Franklin, Clinton, St. Lawrence River Basin, the depths of sand-and-gravel wells Essex, Hamilton, Herkimer, Jefferson, and Lewis Counties sampled range from 34 to 236 ft bls; the depths of bedrock (fig. 7). Major tributaries to the St. Lawrence River include the wells that were sampled range from 80 to 600 ft bls. The bed- St. Regis River, Grass River, Raquette River, and Oswegatchie rock wells are completed in clastic (sandstone), carbonate, or River (fig. 7). Other major contributing tributaries in the crystalline bedrock. Introduction 9

830 8 30 EPLANATION Generalied bedrock geology Carbonate ORLEANS NIAGARA Shale ! Shale and carbonates M155 WAYNE Shale and sandstone Study area boundary MONROE Wells sampled 43 GENESEE AG 25AG 25 Bedrock well sampled and ! .S. Geological Survey well number (table 2) GS 2 AG 266AG 266 Sand and gravel well sampled ! and .S. Geological Survey well number (table 2)

ERIE 52 L11 ONTARIO LIVINGSTON ! !T222 WYOMING

!L151 YATES !14 12 !L142

4230

AG210

AG112

CATTARAUGUS STEUBEN ALLEGANY ! AG 24 AG200 ! AG 25

42 NEW YORK AG 266 PENNSYLVANIA

Base from U.S. Geological Survey digital data, 1983, 1:100,000 Geology modified from Fisher and others, 190 Universal Transverse Mercator projection one 18

0 10 20 MLES

0 10 20 KLOMETERS

Figure 5. Generalized bedrock geology of the Genesee River Basin, New York, and locations of wells sampled in 2015. 10 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

830 8 30 EPLANATION Generalied surficial geology Alluvium and outwash ORLEANS NIAGARA Lacustrine sand, silt, and clay ! ce-contact deposits M155 WAYNE Till

MONROE Bedrock

43 Study area boundary GENESEE Wells sampled AG 25 Bedrock well sampled and GS 2 ! .S. Geological Survey well ! number (table 2) AG 266 Sand and gravel well sampled and .S. Geological Survey ERIE well number (table 2) 52 L11 ONTARIO LIVINGSTON ! !T222 WYOMING

!L151 YATES !14 12 !L142

4230

AG210

AG112

CATTARAUGUS STEUBEN ALLEGANY ! AG 24 AG200 ! AG 25

42 NEW YORK AG 266 PENNSYLVANIA

Base from U.S. Geological Survey digital data, 1983, 1:100,000 Geology modified from Cadwell, 1999 Universal Transverse Mercator projection one 18

0 10 20 MLES

0 10 20 KLOMETERS

Figure 6. Generalized surficial geology of the Genesee River Basin, New York, and locations of wells sampled in 2015. Introduction 11

5 4

Cornwall " 45 CANADA QUEBEC " NEW YORK St Lawrence ValleyMassena "Malone

Lisbon Ogdensburg " CLINTON " " Grass River Potsdam "Canton ONTARIO FRANKLIN St Regis River NEW YORK 4430 Black Raquette River Lake ST LAWRENCE

OswegatchieGouverneur River St Lawrence River " Tupper Lake " Cranberry Tupper Lake Lake Indian River ESSEX

Long 44 Lake JEFFERSON Adirondack Mountains

Raquette " Lake Blue Mountain Lake Lake LEWIS Ontario HERKIMER HAMILTON

WARREN OSWEGO WASHINGTON 4330 ONEIDA Base from U.S. Geological Survey digital data, 1983, 1:100,000 Hydrology from National Hydrography Dataset, 1:100,000 Universal Transverse Mercator projection Topography from National Elevation Dataset one 18

0 10 20 40 MLES

0 10 20 40 KLOMETERS

EPLANATION QC Elevationn feet above the North American ertical Datum of 1

VT Lake Study Ontario area NY NH Study area boundary

Figure 7. Topography and geography of the St. Lawrence River Basin, New York. 12 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

5 4

QUEBEC 45 CANADA ! NEW YORK 25 !ST2065 1544

5 !ST222 !ST2460 ! CLINTON ST0 ! ST64 54 146

ONTARIO NEW ST FRANKLIN YORK 4430 !ST5 ST 66 ST LAWRENCE

! J2146 J1451 ! ST62 !J162 ! ! ST 4 ! L 64 ESSEX J16 01 44 JEFFERSON !

LEWIS HERKIMER HAMILTON

WARREN OSWEGO WASHINGTON 4330 ONEIDA Base from U.S. Geological Survey digital data, 1983, 1:100,000 Geology modified from Fisher and others, 190 Universal Transverse Mercator projection one 18

0 10 20 40 MLES

0 10 20 40 KLOMETERS

EPLANATION

Generalied bedrock geology Study area boundary Carbonate Wells sampled ! Bedrock well sampled and Black shale 25 25 .S. Geological Survey well Shale and sandstone number (table 2)

Sandstone 54 54 Sand and gravel well sampled and .S. Geological Survey Crystalline well number (table 2)

Glacial deposits (bedrock type not mapped)

Figure 8. Generalized bedrock geology of the St. Lawrence River Basin, New York, and locations of wells sampled in 2015. Introduction 13

5 4

QUEBEC 45 CANADA ! NEW YORK 25 !ST2065 1544

5 !ST222 !ST2460 ! CLINTON ST0 ! ST64 54 146

ONTARIO NEW ST FRANKLIN YORK 4430 !ST5 ST 66 ST LAWRENCE

! J2146 J1451 ! ST62 !J162 ! ! ST 4 ! L 64 ESSEX J16 01 44 JEFFERSON !

LEWIS HERKIMER HAMILTON

WARREN OSWEGO WASHINGTON 4330 ONEIDA Base from U.S. Geological Survey digital data, 1983, 1:100,000 Geology modified from Cadwell, 1999 Universal Transverse Mercator projection one 18

0 10 20 40 MLES

0 10 20 40 KLOMETERS

EPLANATION

Generalied surficial geology Study area boundary Alluvium and outwash Wells sampled 25 25 ! Bedrock well sampled and Lacustrine sand, silt, and clay .S. Geological Survey well number (table 2) ce-contact deposits 54 54 Sand and gravel well sampled Till and .S. Geological Survey well number (table 2) Bedrock

Figure 9. Generalized surficial geology of the St. Lawrence River Basin, New York, and locations of wells sampled in 2015. 14 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Methods of Investigation in 2015 (AG 266, AG1129, and WO 352) were also sampled in 2010 (Reddy, 2012). Four St. Lawrence River Basin wells Well-selection criteria, sampling methods, and analytical sampled in 2015 (F 543, F 573, J1736, and ST 378) were also methods were designed to maximize data precision, accuracy, sampled in 2010 (Nystrom, 2012); three of those wells (F 543, and comparability. Groundwater-sample collection and pro- F 573, ST 378) and one other well (ST 366) were sampled cessing followed standard USGS procedures as documented in as part of the 2005–6 round of the study as well (Nystrom, the National Field Manual for the Collection of Water-Quality 2007b). Domestic wells that are completed in sand-and- Data (U.S. Geological Survey, variously dated). Samples were gravel aquifers are often finished with open-ended casing so analyzed at the USGS National Water Quality Laboratory that groundwater enters the well only through the end of the (NWQL) in Denver, Colorado, and other certified laboratories casing. Production wells, however, are typically completed using published methods. with a well screen to maximize the well yield; the difference between the casing depth and the well depth in table 2 is the approximate screened interval for these wells. In some cases, Well Selection production wells with lower yields are completed open-ended in sand-and-gravel aquifers with no screen. Bedrock wells, The 46 wells selected for sampling (figs. 2, 5, and 8) both domestic and production, are completed with a surface represent forested, developed, and agricultural areas (table 2). casing cemented several feet into competent bedrock, and the The final selection of each well for sampling was based on balance of the well is completed as an open hole in bedrock. the availability of well-construction data and hydrogeologic In bedrock wells, groundwater moves mainly through bed information for the well and its surrounding area. The study partings, joints, and other fractures in the rock towards the did not target specific municipalities, industries, or agricultural wellbore under pumping conditions. practices. Wells were selected to represent an approximately equal number of domestic and production wells. The domestic wells were selected on the basis of infor- Sampling Methods mation from the NYSDEC Water Well program, which began in 2000. The program requires that licensed well drillers file a Water-quality samples were collected and processed in report with NYSDEC containing basic information about each accordance with documented USGS protocols (U.S. Geologi- well drilled, such as well and casing depth, diameter, yield, cal Survey, 2006). The samples were collected before any and a driller’s log. Evaluation of data from well-completion water-treatment system to be representative of the native reports identified several hundred wells as potential sampling aquifer water. Samples from domestic wells were collected sites; well owners were sent a letter requesting permission to from a spigot near the pressure tank; samples from production sample the well and a questionnaire about the well. Well own- wells were collected at the spigot or faucet used for collection ers who granted permission were contacted later by phone to of raw-water samples by water managers. verify well information and to arrange for sampling. Samples were collected from garden-hose-thread spigots Production wells considered for sampling were identi- at all sites where possible. Domestic wells were purged by fied through the U.S. Environmental Protection Agency (EPA) pumping groundwater to waste for at least 20 minutes at Safe Drinking Water Information System, the New York State pumping rates ranging from about 2 to 5 gal/min or until at Department of Health (NYSDOH) Drinking Water Protec- least one well-casing volume of water had passed the sampling tion Program, and the NYSDEC Water Well Program. Town point. Generally, three casing volumes were evacuated from officials and (or) water managers were sent letters requesting wells prior to sampling (U.S. Geological Survey, 2006); how- permission to sample a well, and follow-up phone calls were ever, for wells that had been used recently, less than three cas- made to arrange a time for sampling. Well information, such as ing volumes were purged, and wells were sampled when field depth, was provided by water managers if a well-completion physiochemical measurements (for example, temperature, pH, report was unavailable. The aquifer type indicated for sampled specific conductivity) stabilized. During well purging, notes wells was assigned through evaluation of driller’s logs and about the well, surrounding land, and land use were recorded, published geologic maps, including Fisher and others (1970) including a global positioning system measurement of latitude and Cadwell (1999). and longitude. Field measurements of water temperature, The characteristics of the wells sampled, the USGS- pH, specific conductance, and dissolved oxygen concentra- assigned county well numbers, and the type of land cover tion were recorded at the site by using portable instruments surrounding each well are listed in table 2. The depths of the (U.S. Geological Survey, variously dated). wells and the aquifer units from which samples were collected The flow rate for sample collection was adjusted to less are summarized in tables 2 and 3. Two Delaware River Basin than 0.5 gal/min when possible. The sampling tube was then wells sampled in 2015 (SV 534 and SV1689) were also sam- connected to a sample-collection chamber constructed of a pled in 2010 (Nystrom, 2012); one of those wells (SV1689) polyvinyl chloride frame and a clear plastic chamber bag, the was sampled as part of the 2005–6 round of the study as well purpose of which is to minimize the possibility of any airborne (Nystrom, 2007a). Three Genesee River Basin wells sampled contaminants getting into the water samples. The tubing and Methods of Investigation 15 spigot-attachment equipment for each sample were precleaned total organic carbon, trace elements, radon-222, pesticides, by using standard methods (U.S. Geological Survey, 2006). pesticide degradates, and VOCs were analyzed at the USGS Samples were collected and preserved in the sampling NWQL in Denver, Colo. Selected dissolved gases were ana- chamber according to standard USGS procedures (U.S. lyzed at the USGS Chlorofluorocarbon Laboratory in Reston, Geological Survey, 2006). Samples for nutrient, major- Virginia. Gross-alpha (gross-α) and gross-beta (gross-β) ion, and some trace-element analyses were filtered through radioactivities were analyzed at ALS Environmental in Fort disposable (one-time use) 0.45-micrometer (µm) pore-size Collins, Colo. Samples were analyzed for indicator bacteria at polyether sulfone capsule filters that were preconditioned in the following NYSDOH-certified laboratories: Delaware River the laboratory with 3 liters (L) of deionized water on the day Basin samples were analyzed at the St. Peter’s Bender Labora- of sample collection and stored on ice until use in the field. tory in Albany, New York; Genesee River Basin samples were Since the time of the sampling for this project, advanced analyzed at Community Science Institute in Ithaca, N.Y.; preconditioning of capsule filters prior to use has been found St. Lawrence River Basin samples were analyzed at the Life to be a source of total nitrogen and total Kjeldahl nitrogen Science Laboratories in Waddington, N.Y. contamination (U.S. Geological Survey, Office of Water Anion concentrations were measured by ion-exchange Quality, Water-Quality Information Note 2017.03, written chromatography, and cation concentrations were measured commun., 2017). Samples for pesticide analyses were filtered by inductively coupled plasma-atomic emission spectrom- through baked 0.7-µm pore-size glass-fiber filters. Ultrapure etry (ICP–AES), as described in Fishman (1993). Color was nitric acid preservation was required for trace-element determined by visual comparison using method I–1250–85 samples, except mercury, which was preserved with ultrapure (Fishman and Friedman, 1989). Nutrients were analyzed by hydrochloric acid. Hydrochloric acid was added to samples colorimetry, as described by Fishman (1993), and Kjeldahl analyzed for VOCs to reduce the sample pH below 2.0 and digestion with photometric finish, as described by Patton and kill bacteria that might degrade VOCs. Samples for major- Truitt (2000). Nitrate was calculated by subtracting the nitrite cation analysis and some samples for radiochemical analysis from the measured values of nitrate plus nitrite. Total organic were preserved with ultrapure nitric acid. Acid preservative carbon samples were analyzed by high-temperature combus- was added after the collection of other samples to prevent the tion and catalytic oxidation for measurement by infrared possibility of cross contamination by the acid preservative; detection according to Standard Method 5310B (American for example, samples preserved with nitric acid were acidified Public Health Association, 1998). Mercury concentrations after the collection of samples for nutrient analysis. Water were measured through cold vapor-atomic fluorescence samples for radon analysis were collected through a septum spectrometry according to methods described by Garbarino chamber with a glass syringe, according to standard USGS and Damrau (2001). Arsenic, chromium, and nickel were procedures (U.S. Geological Survey, 2006). Bottles containing analyzed by use of collision/reaction cell inductively coupled water samples for the analysis of dissolved gases were filled plasma-mass spectrometry, as described by Garbarino and and sealed while submerged in a beaker of well water to others (2006). The remaining trace elements were analyzed by prevent exposure to the atmosphere. Samples for bacterial ICP–AES (Struzeski and others, 1996), inductively coupled analysis were collected in accordance with NYSDEC and plasma-optical emission spectrometry, and inductively NYSDOH protocols (American Public Health Association, coupled plasma-mass spectrometry (Garbarino and Struzeski, 1998), except that the tap from which each water sample was 1998). Procedures for in-bottle digestions for trace-element collected was not flame sterilized. Water samples for bacterial analyses described by Hoffman and others (1996) were fol- analysis were collected in sterilized bottles provided by the lowed. Radon-222 activities were measured through liquid- NYSDOH-certified analyzing laboratory. After collection, all scintillation counting (ASTM International, 2006). Samples water samples except those for radiochemical analyses were for pesticide analyses were processed as described by Wilde and others (2009) and were analyzed by gas chromatography- chilled to 4 degrees Celsius (°C) or less and were kept chilled mass spectrometry (GC–MS) and high-performance liquid until delivery to the analyzing laboratory. Bacterial samples chromatography-mass spectrometry, as described by Zaugg were hand delivered to the analyzing laboratory within 6 hours and others (1995), Sandstrom and others (2001), and Furlong of collection; all other samples were shipped by overnight and others (2001). VOCs were analyzed by GC–MS according delivery to the designated laboratories. to methods described by Connor and others (1998). Gross-α and gross-β radioactivities were measured Analytical Methods according to EPA method 900.0 (U.S. Environmental Protec- tion Agency, 1980). Carbon dioxide and methane concentra- Samples were measured for 148 physiochemical proper- tions were measured through gas chromatography with flame ties and constituents, including dissolved gases, major ions, ionization detection; dissolved nitrogen gas and argon con- nutrients, trace elements, pesticides, pesticide degradates, centrations were measured using gas chromatography with VOCs, radionuclides, and bacteria. Water temperature, pH, thermal conductivity detection (Busenberg and others, 1998). dissolved oxygen concentration, and specific conductance Indicator bacteria samples were tested for total coliforms, were measured at the sampling site. Major ions, nutrients, fecal coliforms (also known as thermotolerant coliforms), 16 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 2. Description of wells from which water samples were collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.—Continued

[Well locations are shown in figures 2 and 3 (Delaware Basin), figures 5 and 6 (Genesee River Basin), and figures 8 and 9 (St. Lawrence River Basin). Well types: P, production; D, domestic; M, municipal. Land-cover categories: D, developed; F, forested; A, agricultural; W, open water; WL, wet- lands. --, unknown]

Well Casing Date depth, depth, Land cover,2 percentage by category, Station Well sampled in feet in feet Well within 0.5-mile radius surrounding the well identification Bedrock type number1 (mm/dd/ below below type number yyyy) land land surface surface D F A W WL Delaware River Basin Sand-and-gravel wells D 276 420357075245901 10/19/2015 120 110 P -- 45 22 23 5 5 SV 39 415601074544901 10/20/2015 90 -- P -- 5 3 14 1 SV 534 414504074355301 10/21/2015 42 34 P -- 1 4 31 3 3 Bedrock wells D 199 420924074315601 10/14/2015 200 -- P Shale and sandstone 20 80 D1584 422309074525301 10/13/2015 195 47 D Shale and sandstone 3 55 3 4 D1997 420940074492001 10/6/2015 198 90 D Shale and sandstone 1 9 2 D2321 420302075214301 10/19/2015 200 100 D Shale and sandstone 4 8 1 1 O10369 412234074374001 10/5/2015 320 100 D Shale and sandstone 23 1 4 2 SV 132 414831074531101 10/21/2015 400 -- P Shale and sandstone 81 12 SV1689 415220075034801 10/7/2015 380 10 D Shale and sandstone 4 9 Genesee River Basin Sand-and-gravel wells AG 266 420219077462301 7/21/2015 78 -- P -- 13 0 2 AG 274 421139078082901 7/20/2015 85 85 P -- 5 4 48 AG1129 422018078071901 7/15/2015 199 198 P -- 29 11 55 5 AG2109 422729077465601 7/28/2015 94 92 P -- 18 20 5 WO 352 424924078045901 7/14/2015 25 -- P -- 14 43 3 WO1329 423606078044901 5/27/2015 115 103 P -- 5 2 55 111 2 Bedrock wells AG 275 420927077471501 7/27/2015 262 49 P Shale and sandstone 31 50 1 12 AG2300 421317077481701 6/16/2015 123 55 D Shale and sandstone 2 58 40 GS 289 425437078001601 6/24/2015 50 -- P Shale 12 19 4 4 LV1313 424550077414701 7/13/2015 110 76.5 D Shale and sandstone 4 4 50 LV1351 423823077520501 5/26/2015 105 42.5 D Shale and sandstone 44 48 1 LV1423 423500077472501 6/9/2015 75 19 D Shale and sandstone 3 45 52 1 MO1855 430933077480001 6/17/2015 50 19 D Carbonate 9 8 OT2282 424349077310401 6/10/2015 89 60.5 D Shale 11 44 1 45 WO1483 423559078140601 7/1/2015 130 30.5 D Shale and sandstone 4 24 2 Methods of Investigation 17

Table 2. Description of wells from which water samples were collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.—Continued

Well Casing Date depth, depth, Land cover,2 percentage by category, Station Well sampled in feet in feet Well within 0.5-mile radius surrounding the well identification Bedrock type number1 (mm/dd/ below below type number yyyy) land land surface surface D F A W WL St. Lawrence River Basin Sand-and-gravel wells F 543 443758074273001 11/18/2015 90 78 M -- 8 2 F 573 444455074124102 11/18/2015 236 152 P -- 88 2 3 F1468 444204074073301 11/18/2015 140 133.5 D -- 8 31 35 2 F1544 445916074095001 11/16/2015 151.6 151.6 D -- 1 24 43 11 J1736 440229075501101 11/5/2015 41 20 P -- 54 21 21 4 ST 366 443021075042901 11/17/2015 34 8 P -- 1 8 12 1 9 ST 378 443306074555101 11/17/2015 65 54 P -- 12 0 5 13 9 Bedrock wells F 25 445933074291801 11/16/2015 260 80 P Carbonate 21 18 38 4 10 H 801 435928074263901 11/2/2015 482 60 D Crystalline 2 93 4 J1451 441758075550101 11/4/2015 80 20 D Sandstone 3 32 4 18 J1628 441307076082501 11/4/2015 220 20 D Sandstone 4 55 15 2 J2146 441636075375701 11/4/2015 165 92 D Crystalline 2 39 38 1 19 L 647 440824075232501 11/5/2015 290 20 D Carbonate 1 43 44 11 ST 943 441301074364801 11/2/2015 600 96 P Crystalline 3 20 ST2065 445435074540402 11/19/2015 256 39 D Carbonate 15 41 20 11 13 ST2227 444439074594601 11/16/2015 260 43 P Carbonate 38 3 9 4 11 ST2460 444456074400301 11/3/2015 98 85 D Sandstone 1 0 34 4 ST3358 442844075350101 11/19/2015 80 20 D Carbonate 5 40 9 1 4 ST3627 441245075142601 11/3/2015 120 100 D Carbonate 1 9 8 2 20 ST3674 443927075291301 11/16/2015 85 20 D Carbonate 5 38 32 12 14 ST3703 444200075114801 11/3/2015 197 70 D Sandstone 2 9 5 33 1Prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; GS, Genesee; H, Hamilton; J, Jefferson; L, Lewis; LV, Livingston; MO, Monroe; O, Orange; OT, Ontario; ST, St. Lawrence; SV, Sullivan; WO, Wyoming. Number is local well-identification number assigned by the U.S. Geological Survey. 2Determined from the National Land Cover Database (Homer and others, 2015). 18 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 3. Summary of 46 wells from which water samples were collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

[bls, below land surface]

Number of wells Basin and type of well Production Domestic Total Delaware River Basin Wells completed in sand and gravel (depth 42 to 120 feet bls) 3 0 3 Wells completed in bedrock (depth 195 to 400 feet bls) 2 5 7 Total for all well types 5 5 10 Genesee River Basin Wells completed in sand and gravel (depth 25 to 199 feet bls) 6 0 6 Wells completed in bedrock (depth 50 to 262 feet bls) 2 7 9 Total for all well types 8 7 15 St. Lawrence River Basin Wells completed in sand and gravel (depth 34 to 236 feet bls) 15 2 7 Wells completed in bedrock (depth 80 to 600 feet bls) 3 11 14 Total for all well types 8 13 21 Total for all basins 21 25 46 1Includes one municipal well. and Escherichia coli (E. coli) by using membrane filtration “V” remark code in the associated tables and discussion in and Standard Method 9222; a heterotrophic plate count test this report. The “V” remark codes indicate that a value may (SM 9215 B) also was done (American Public Health Associa- be affected by contamination; the analyte was detected in tion, 1998). environmental samples and the associated blanks. An additional emphasis was placed on analyzing blanks specifically for ammonia and ammonia-plus-organic nitrogen Quality-Control Samples during the 2015 round of sampling to investigate an issue with low-level ammonia detections in field blanks from past rounds In addition to the 46 groundwater samples, 3 field blank of sampling. A combination of field blanks, equipment blanks, samples and 1 replicate sample were collected for quality and source solution blanks were analyzed with 30 blank sam- assurance. Additionally, 27 topical blank samples were ples from all 3 basins (3 blanks from the previously mentioned collected for analysis of ammonia and ammonia-plus-organic field blanks and 27 additional blanks) for ammonia and ammo- nitrogen, and 3 partial replicates were collected for analysis of nia-plus-organic nitrogen. Thirteen of the blank samples had bacteria, radon, gross-α, gross-β, and dissolved gasses. Only an ammonia concentration right at the LRL (0.01 mg/L), and the following constituents were detected in blanks; no other one blank sample had a slightly higher detection (0.02 mg/L). constituents were detected in any blanks. Silica was detected Ammonia was detected in all types of blanks, including source in all three of the complete field blanks, one of which was solution blanks, indicating that the blank water itself was collected in each of the three basins. Silica was measured contaminated, possibly from atmospheric sources. Ammonia at 0.050 milligram per liter (mg/L) in the blank collected in plus organic nitrogen was detected in three field blanks, one the Delaware River Basin, 0.523 mg/L in the blank collected from the Delaware River Basin (0.10 mg/L) and two from the in the Genesee River Basin, and 0.078 mg/L in the blank Genesee River Basin (0.07 and 0.25 mg/L). These ammonia collected in the St. Lawrence River Basin. The laboratory plus organic nitrogen detections in blanks were found to be reporting level (LRL), which is the concentration at which the result of contamination from the advanced precondition- the false negative error rate is minimized to be no more than ing of capsule filters with deionized water prior to filtration 1 percent of the reported results (Childress and others, 1999), (U.S. Geological Survey, Office of Water Quality, Water- for silica is 0.018 mg/L. The minimum silica concentration Quality Information Note 2017.03, written commun., 2017). It in the environmental samples was 3.59 mg/L. Manganese is possible that the ammonia blank detections are also a result (unfiltered) was measured at 13.5 micrograms per liter (µg/L) of this practice. The LRL for ammonia plus organic nitrogen in one of the field blanks, collected in the Delaware River is 0.07 mg/L. For both ammonia and ammonia-plus-organic Basin. Six samples from the Delaware River Basin had nitrogen, a “V” remark code was assigned to detections to manganese detections less than 13.5 µg/L and were given a indicate possible contamination. Groundwater Quality 19

A complete replicate sample was collected at one Dela- Physiochemical Properties ware River Basin well, and three partial replicate samples were collected, one in each basin. The variability between the Groundwater samples were analyzed in the field for complete replicate samples from the Delaware River Basin physiochemical properties, including water temperature, pH, well was less than 12 percent for all constituents. For the specific conductance, and dissolved oxygen. Samples were partial replicates, which only compared results from bacteria, collected for analysis of color. Qualitative assessment of the radon, gross-α, gross-β, and dissolved gas analyses, vari- presence of hydrogen sulfide (based on odor) was noted. ability between replicate samples was less than 20 percent Results of analyses are reported in table 5 and in appendix for all constituents with the exception of heterotrophic plate table 1.2. The numbers of samples that exceeded drinking- count (in samples from all three basins) and low-level gross-α water standards for physiochemical properties are reported in and gross-β (in samples from the Delaware and St. Lawrence table 6. No drinking-water standards exist for specific conduc- River Basins). tance or water temperature. Most samples from the Delaware River Basin had a color of less than (<) 1 platinum-cobalt (Pt-Co) unit (tables 5, 6, and appendix table 1.2). One sample, from a bedrock well (D 199) Groundwater Quality had a color of 2 Pt-Co units. Two samples, one from a bedrock well (SV 132) and one from a sand-and-gravel well (SV 39), Many of the constituents for which the groundwater had color of 5 Pt-Co units. One sample, from a bedrock well samples were analyzed were not detected in any sample. Some (O10369), had a color of 15 Pt-Co units, which was equal concentrations are reported as “E” for estimated. Estimated to the EPA SDWS of 15 Pt-Co units (U.S. Environmental concentrations are typically reported when the detected Protection Agency, 2012). Sample pH was typically slightly value is less than the established LRL or when recovery of a below neutral (median of 6.6 for sand-and-gravel wells, 6.8 compound has been shown to be highly variable (Childress for bedrock wells) and ranged from 5.3 to 7.2. The pH values and others, 1999). Some concentrations are reported with a for samples from two bedrock wells (D1584 and O10369) “V” remark code, which indicates that a value may be affected and one sand-and-gravel well (SV 534) were 5.7, 5.3 and by contamination; the analyte was detected in environmental 5.4, respectively, and are lower than the EPA SDWS range of samples and the associated blank sample. 6.5–8.5 for pH (U.S. Environmental Protection Agency, 2012). Concentrations of some constituents exceeded maximum Specific conductance ranged from 91 to 287 microsiemens per contaminant levels (MCLs) or secondary drinking-water stan- centimeter at 25 degrees Celsius (µS/cm at 25 °C); the median dards (SDWSs) set by the EPA (U.S. Environmental Protec- specific conductance was 282 µS/cm at 25 °C for sand-and- tion Agency, 2012) or NYSDOH (New York State Department gravel wells and 158 µS/cm at 25 °C for bedrock wells. Water of Health, 2011), or proposed alternative MCLs set by the temperature ranged from 8.4 to 12.6 °C; the median tempera- EPA (U.S. Environmental Protection Agency, 1999) (table 4). ture was 10.7 °C for sand-and-gravel wells and 10.2 °C for MCLs are enforceable standards for finished water in public bedrock wells. Hydrogen sulfide odor was not detected in any water supplies; they are not enforceable for private home- wells sampled in the Delaware River Basin. Most samples from the Genesee River Basin had a owner wells but are presented here as standards for evalua- color of <1 Pt-Co units (tables 5, 6, and appendix table 1.2). tion of the water-quality results. SDWSs are nonenforceable Three samples, two from sand-and-gravel wells (AG1129, drinking-water standards that typically relate to aesthetic con- AG2109) and one from a bedrock well (LV1423), had colors cerns such as taste, odor, or staining of plumbing fixtures. Well of 2 Pt-Co units. One sample from a bedrock well (LV1313) owners were notified promptly if any constituent exceeded had a color of 8 Pt-Co units. One sample from a bedrock well EPA or NYSDOH MCLs. Copies of the complete analytical (LV1351) had a color of 15 Pt-Co units, which is equal to the results were mailed to each well owner. EPA SDWS. Sample pH was typically near neutral (median The results of analyses of the 46 groundwater samples of 7.9 for sand-and-gravel wells, 7.4 for bedrock wells) and collected in the Delaware, Genesee, and St. Lawrence River ranged from 7.0 to 8.2. Specific conductance ranged from Basins from May through November 2015 are presented in 268 to 2,270 µS/cm at 25 °C; the median specific conductance appendix 1 (tables 1.1 through 1.9) and are available online was 435 µS/cm at 25 °C for sand-and-gravel wells and through the USGS National Water Information System 744 µS/cm at 25 °C for bedrock wells. Water temperature (https://nwis.waterdata.usgs.gov/ny/nwis/qw; U.S. Geological ranged from 9.8 to 16.1 °C; the median temperature was Survey, 2018) by using the station identification number given 10.5 °C for sand-and-gravel wells and 13.1 °C for bedrock in table 2. Of the 148 constituents and physiochemical proper- wells. Hydrogen sulfide odor was detected in two sand-and- ties analyzed for, 78 (or 53 percent) were not detected at levels gravel wells (AG 274, AG2109) and four bedrock wells greater than the LRLs in any sample (appendix table 1.1). (GS 289, LV1351, OT2282, WO1483). Results for the remaining 70 constituents and properties that Most samples from the St. Lawrence River Basin had a were detected in the Delaware, Genesee, and St. Lawrence color of <1 Pt-Co units (tables 5, 6, and appendix table 1.2). River Basins are presented in appendix tables 1.2 through 1.9. Two samples from bedrock wells (J1628, ST3703) had low 20 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 4. Constituents that exceeded primary, secondary, and (or) proposed drinking-water standards in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.—Continued

[Well locations are shown in figures 2 and 3 (Delaware River Basin), figures 5 and 6 (Genesee River Basin), and figures 8 and 9 (St. Lawrence River Basin). Well types: P, production; D, domestic; M, municipal. --, not applicable; pAMCL, proposed alternative maximum contaminant level; pMCL, proposed maximum contaminant level; f, in filtered water; u, in unfiltered water]

Well Well Bedrock type Constituents that exceeded drinking-water standards number1 type Delaware River Basin Sand-and-gravel wells D 276 P -- Radon5 (pAMCL) SV 39 P -- Manganese (f,u),6 radon5 (pAMCL) SV 534 P -- pH,6 radon5 (pAMCL) Bedrock wells D 199 P Shale and sandstone Radon5 (pAMCL) D1584 D Shale and sandstone pH,6 radon5 (pAMCL), total coliform2,3,4 D1997 D Shale and sandstone Radon5 (pAMCL), total coliform2,3,4 D2321 D Shale and sandstone Iron (u),3,6 manganese (f,u),6 radon5 (pAMCL) O10369 D Shale and sandstone pH,6 iron (f,u),3,6 manganese (f,u),6 radon5 (pAMCL) SV 132 P Shale and sandstone Radon5 (pAMCL) SV1689 D Shale and sandstone Aluminum,6 radon5 (pAMCL) Genesee River Basin Sand-and-gravel wells AG 266 P -- Radon5 (pAMCL) AG 274 P -- Iron (f,u),3,6 manganese (f,u),6 radon5 (pAMCL) AG1129 P -- Arsenic,2,3 sodium,7 methane,8 iron (f,u),3,6 manganese (u),6 radon5 (pAMCL) AG2109 P -- Iron (f,u),3,6 manganese (f,u),6 radon5 (pAMCL) WO 352 P -- Radon5 (pAMCL) WO1329 P -- Iron (f,u),3,6 manganese (f,u)6 Bedrock wells AG 275 P Shale and sandstone Sodium,7 radon5 (pAMCL), total coliform2,3,4 AG2300 D Shale and sandstone Aluminum,6 iron (u),3,6 manganese (u),3,6 radon5 (pAMCL) GS 289 P Shale Sodium,7 dissolved solids,6 iron (f,u),3,6 total coliform2,3,4 LV1313 D Shale and sandstone Methane,8 manganese (f,u)6 LV1351 D Shale and sandstone Arsenic,2,3 iron (f,u),3,6 manganese (f,u),6 radon5 (pAMCL) LV1423 D Shale and sandstone Manganese (f,u),6 radon5 (pAMCL), total coliform,2,3,4 fecal coliform,2,3,4 E. coli2,3,4 MO1855 D Carbonate Sodium,7 dissolved solids,6 radon,5 total coliform2,3,4 OT2282 D Shale Methane,8 sodium,7 dissolved solids,6 chloride,3,6 manganese (f,u),6 aluminum,6 iron (f,u),3,6 radon5 (pAMCL), total coliform2,3,4 WO1483 D Shale and sandstone Sodium,7 aluminum,6 iron (u),3,6 radon5 (pAMCL), total coliform2,3,4 Groundwater Quality 21

Well Well Bedrock type Constituents that exceeded drinking-water standards number1 type St. Lawrence River Basin Sand-and-gravel wells F 543 M -- pH,6 radon5 (pAMCL) F 573 P -- Radon5 (pAMCL) F1468 D -- Radon5 (pAMCL) F1544 D -- Manganese (f,u),6 radon5 (pAMCL) J1736 P -- Sodium,7 dissolved solids,6 chloride,3,6 manganese (f,u)6 ST 366 P -- Radon5 (pAMCL) ST 378 P -- Radon5 (pAMCL) Bedrock wells F 25 P Carbonate -- H 801 D Crystalline Radon5 (pAMCL) J1451 D Sandstone Radon5 (pAMCL) J1628 D Sandstone Sodium,7 dissolved solids6 J2146 D Crystalline Dissolved solids,6 manganese (f,u),6 radon5 (pAMCL) L 647 D Carbonate Radon5 (pAMCL) ST 943 P Crystalline Radon5 (pAMCL) ST2065 D Carbonate Sodium,7 dissolved solids,6 chloride,3,6 sulfate3,6 ST2227 P Carbonate Iron (f,u),3,6 manganese (f,u)6 ST2460 D Sandstone Radon5 (pAMCL) ST3358 D Carbonate Dissolved solids,6 nitrate,2,3 radon5 (pAMCL), total coliform,2,3,4 fecal coliform,2,3,4 E. coli2,3,4 ST3627 D Carbonate Radon5 (pAMCL) ST3674 D Carbonate Iron (f,u)3,6 ST3703 D Sandstone -- 1Prefix denotes county: AG, Allegany; D, Delaware; F, Franklin; GS, Genesee; H, Hamilton; J, Jefferson; L, Lewis; LV, Livingston; MO, Monroe; O, Orange; OT, Ontario; ST, St. Lawrence; SV, Sullivan; WO, Wyoming. Number is local well-identification number assigned by the U.S. Geological Survey. 2U.S. Environmental Protection Agency (2012) maximum contaminant level. 3New York State Department of Health (2011) maximum contaminant level. 4Maximum contaminant level exceedances for bacteria in public drinking-water supplies are generally defined in terms of a certain number of positive samples per month on the basis of the number of samples collected. 5U.S. Environmental Protection Agency (1999) proposed alternative maximum contaminant level of 300 picocuries per liter for areas that do not implement an indoor-air radon mitigation program. 6U.S. Environmental Protection Agency (2012) secondary drinking water standard. 7U.S. Environmental Protection Agency (2012) drinking water advisory taste threshold. 8Methane concentration above recommended monitoring concentration (Eltschlager and others, 2001). 22 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015 - 9.2 8.3 1.39 1.73

11.6 12 55.76

169 mum Maxi 5,010 0.4 7.4 9.6 0.820 0.007 15.5 24.73 <1 Median 629 (14 samples) Bedrock aquifers - 6.7 8.3 0.4 0.738 mum Mini 20.78 <1 <0.3 <0.001 124

8.0 0.833 0.501 11.6 12 12.8 57 24.41 mum Maxi- 1,620 St. Lawrence River Basin 0 3.6 7.4 9.0 7.8 0.743 21.20 <0.001 Median 229 (7 samples) - Sand-and-gravel aquifers 6.4 7.3 2.1 0.724 mum Mini 92 19.85 <1 <0.3 <0.001 6.3 8.1 0.856 15 16.1 29.32 54.5

mum 133 Maxi- 2,270 0.7 7.4 0.777 0.813 13.1 21 22.86 <1 Median 744 (9 samples) Bedrock aquifers - 7.0 3.1 0.072 mum Mini 11.1 25.54 <1 <0.3 <0.001 453 -

2 3.6 8.2 0.755 mum 13.1 14 24.21 53.4 Maxi Genesee River Basin 819 0.6 7.9 5.95 0.748 0.086 10.5 22.53 <1 Median 435 (6 samples) - 0.4 7.0 9.8 2.1 0.642 0.001 Sand-and-gravel aquifers mum Mini 16.28 <1 268 - 7.7 7.2 0.839 0.522

mum 11.5 15 26.51 Maxi 233 128 4.1 6.8 0.765 10.2 13 21.52 <1 <0.001 Median 158 (7 samples) - Bedrock aquifers 5.3 8.4 7.8 0.686 mum Mini 91 18.59 <1 <0.3 <0.001

- 5 6.0 6.6 0.724 0.043 mum 12.6 94 20.39 Maxi 287 Delaware River Basin 4.4 6.6 0.722 0.011 10.7 14 20.00 <1 Median 282 (3 samples) - 2.7 5.4 0.665 Sand-and-gravel aquifers mum Mini 10.3 14 18.29 <1 <0.001 144 Summary statistics for physiochemical properties of and dissolved gases in groundwater samples collected the Delaware, Genes ee, St. Lawrence River Basins, - - values exceed one or more drinking-water or safety standards. All concentrations in unfiltered water; Pt-Co units, platinum-cobalt units; mg/L, milligram per liter; µS/cm at 25 ºC, microsiemens centimeter values exceed one or more drinking-water safety standards. filtered, Pt-Co units oxygen, mg/L conduc tance, µS/cm at 25 °C ture, °C dioxide, mg/L mg/L gas, mg/L mg/L Constituent Color, Color, Dissolved pH Specific Tempera Carbon Argon, Nitrogen Methane, Bold Table 5. Table 2015. New York, [ at 25 degrees Celsius; °C, degree <, value less than laboratory reporting level] Groundwater Quality 23

Table 6. Drinking-water standards for physiochemical properties and dissolved gases and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

[All concentrations in unfiltered water. Pt-Co units, platinum-cobalt units; mg/L, milligram per liter]

Number of samples exceeding drinking-water standards Drinking-water Constituent standard All samples Delaware Basin Genesee River Basin St. Lawrence River Basin (46 samples) (10 samples) (15 samples) (21 samples) Color, filtered, Pt-Co units 115 0 0 0 0 pH 16.5–8.5 4 3 0 1 Methane, mg/L 228 3 0 3 0 1U.S. Environmental Protection Agency (2012) secondary drinking water standard. 2Methane recommended monitoring concentration (Eltschlager and others, 2001). colors of 2 and 5 Pt-Co units, respectively. Four samples, two for nitrogen, 13 mg/L for carbon dioxide, 0.765 mg/L for from sand-and-gravel wells (F1468, F1544) and two from argon, and <0.001 mg/L for methane. bedrock wells (ST2227, ST3674), had higher colors ranging In the Genesee River Basin, dissolved oxygen concen- from 8 to 12 Pt-Co units. No samples from the St. Lawrence trations ranged from <0.3 to 6.3 mg/L (table 5 and appendix River Basin exceeded the EPA SDWS for color. Sample pH table 1.2), and samples in sand-and-gravel wells (median was typically near neutral (median of 7.4 for sand-and-gravel 0.6 mg/L) were typically similar to samples from bedrock wells, 7.4 for bedrock wells) and ranged from 6.4 to 8.3. The wells (median 0.7 mg/L). Median concentrations of dis- pH value for a sample from one sand-and-gravel well (F 543) solved gases in samples from sand-and-gravel wells were was 6.4, which is lower than the EPA SDWS range for pH. 22.53 mg/L for nitrogen, 5.95 mg/L for carbon dioxide, Specific conductance ranged from 92 to 5,010 µS/cm at 25 °C; 0.748 mg/L for argon, and 0.086 mg/L for methane. Median the median specific conductance was 229 µS/cm at 25 °C for concentrations of dissolved gases in samples from bedrock sand-and-gravel wells and 629 µS/cm at 25 °C for bedrock wells were 22.86 mg/L for nitrogen, 21 mg/L for carbon wells. Water temperature ranged from 7.3 to 12.8 °C; the dioxide, 0.776 mg/L for argon, and 0.813 mg/L for methane. median temperature was 9.0 °C for sand-and-gravel wells and Methane was detected in samples from 14 of the 15 wells, 9.6 °C for bedrock wells. Hydrogen sulfide odor was detected and 8 of those detections were at trace level. Although the in one sand-and-gravel wells (F1544) and six bedrock wells EPA and NYSDOH do not have MCLs for methane, dissolved (F 25, J1628, J2146, ST2065, ST2227, ST2460). methane concentrations greater than 28 mg/L can pose explo- sion hazards as a result of methane accumulation in confined spaces (Eltschlager and others, 2001). The U.S. Department of Dissolved Gases Interior, Office of Surface Mining Reclamation and Enforce- ment, recommends that methane concentrations ranging from Groundwater samples were collected and analyzed for 10 to 28 mg/L in water signify an action level where the carbon dioxide, argon, nitrogen, and methane—dissolved situation should be closely monitored; if the concentration oxygen was measured in the field. Results are reported in increases, enclosed areas should be vented to prevent methane table 5 and appendix table 1.2. The concentrations of carbon gas buildup (Eltschlager and others, 2001). The concentra- dioxide, argon, nitrogen gas, and methane were determined tions of methane in the two duplicate samples from two twice for each site; therefore, the statistics given include two bedrock wells (OT2282, 54.5 and 52.6 mg/L; LV1313, 28.2 samples per well. These data are listed in appendix table 1.2. and 28.1 mg/L), and from one sand-and-gravel well (AG1129, The number of samples that exceeded drinking-water stan- 53.4 and 53.6 mg/L) were greater than the safety threshold of dards for methane is reported in table 6. No drinking-water 28 mg/L (table 6). standards exist for dissolved oxygen, carbon dioxide, argon, In the St. Lawrence River Basin, dissolved oxygen and nitrogen gas. concentrations ranged from <0.3 to 11.6 mg/L (table 5 and In the Delaware River Basin, dissolved oxygen concen- appendix table 1.2) and typically were greater in samples from trations ranged from <0.3 to 7.7 mg/L (table 5 and appen- sand-and-gravel wells (median 3.6 mg/L) than samples from dix table 1.2) and typically were similar in samples from bedrock wells (median 0.4 mg/L). Median concentrations sand-and-gravel wells (median 4.4 mg/L) and bedrock wells of dissolved gases in samples from sand-and-gravel wells (median 4.1 mg/L). Median concentrations of dissolved gases were 21.20 mg/L for nitrogen, 7.8 mg/L for carbon dioxide, in samples from sand-and-gravel wells were 20.00 mg/L for 0 743 mg/L for argon, and <0.001 mg/L for methane. Median nitrogen, 14 mg/L for carbon dioxide, 0.722 mg/L for argon, concentrations of dissolved gases in samples from bedrock and 0.011 mg/L for methane. Median concentrations of dis- wells were 24.73 mg/L for nitrogen, 15.5 mg/L for carbon solved gases in samples from bedrock wells were 21.52 mg/L dioxide, 0.820 mg/L for argon, and 0.007 mg/L for methane. 24 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Major Ions and Dissolved Solids not exceed established drinking-water standards in any sample (table 8 and appendix table 1.3). Groundwater samples were analyzed for anions includ- For samples in the Genesee River Basin, 2 samples were ing bicarbonate, chloride, fluoride, silica, and sulfate; cations classified as “moderately hard,” 3 samples as “hard” (121 to including calcium, magnesium, potassium, and sodium; hard- 180 mg/L as CaCO3), and 10 samples as “very hard” (greater ness; alkalinity; and dissolved solids. Results for dissolved than [>] 180 mg/L as CaCO3) (Hem, 1985). The median concentrations of major ions, hardness, alkalinity, and dis- hardness was 206 mg/L as CaCO3 for sand-and-gravel wells solved solids are reported in table 7 and in appendix table 1.3. and 221 mg/L as CaCO3 for bedrock wells; and the maximum

The numbers of samples that exceeded drinking-water hardness was 493 mg/L as CaCO3. Alkalinity ranged from standards for major ions and dissolved solids are reported in 58.9 to 579.7 mg/L as CaCO3; the median was 165.0 mg/L table 8. No drinking-water standards exist for calcium, magne- as CaCO3 for sand-and-gravel wells and 243.6 mg/L as sium, potassium, bicarbonate, silica, hardness, or alkalinity. CaCO3 for bedrock wells. Dissolved solids concentrations In the Delaware River Basin, the anions detected in the ranged from 159 to 1,280 mg/L with a median of 244 mg/L highest concentrations were bicarbonate (median of 36 mg/L for sand-and-gravel wells and 456 mg/L for bedrock wells. in sand-and-gravel wells, 50 mg/L in bedrock wells) and Dissolved solids concentration in three samples from bedrock chloride (median of 54.6 mg/L in sand-and-gravel wells, wells (GS 289, 963 mg/L; MO1855, 613 mg/L; OT2282, 9.21 mg/L in bedrock wells) (table 7 and appendix table 1.3). 1,280 mg/L) exceeded the EPA SDWS for total dissolved The cations detected in the highest concentrations were solids of 500 mg/L (U.S. Environmental Protection Agency, calcium (median of 16.0 mg/L in sand-and-gravel wells, 2012; table 8 and appendix table 1.3). 12.3 mg/L in bedrock wells) and sodium (median of 21.4 mg/L In the St. Lawrence River Basin, the anions detected in sand-and-gravel wells, 8.22 mg/L in bedrock wells). The with the highest concentrations were bicarbonate (median concentrations of sodium, chloride, fluoride, and sulfate did of 118 mg/L in sand-and-gravel wells, 224 mg/L in bedrock not exceed established drinking-water standards in any sample wells) and sulfate (median of 7.74 mg/L in sand-and-gravel (table 8 and appendix table 1.3). wells, 37.8 mg/L in bedrock wells) (table 7 and appendix For samples in the Delaware River Basin, seven samples table 1.3). The cations detected in the highest concentrations were classified as “soft” (0 to 60 mg/L as calcium carbonate, were calcium (median of 28.0 mg/L in sand-and-gravel

[CaCO3]) and three as “moderately hard” (61 to 120 mg/L as wells, 71.8 mg/L in bedrock wells), magnesium (median of

CaCO3) (Hem, 1985). The median hardness was 50.7 mg/L 9.33 mg/L in sand-and-gravel wells, 22.7 mg/L in bedrock as CaCO3 for sand-and-gravel wells and 41.2 mg/L as CaCO3 wells), and sodium (median of 4.17 mg/L in sand-and-gravel for bedrock wells; the maximum hardness was 87.4 mg/L as wells, 23.4 mg/L in bedrock wells). The concentration of

CaCO3 (bedrock well, D2321; appendix table 1.3). Alkalin- sodium in one sample from a sand-and-gravel well (J1736, ity ranged from 2.65 to 26.4 mg/L as CaCO3; the median was 168 mg/L) and two samples from bedrock wells (J1628,

21.4 mg/L as CaCO3 for sand-and-gravel wells and 8.22 mg/L 69.5 mg/L; and ST2065, 514 mg/L) exceeded the EPA as CaCO3 for bedrock wells. Dissolved solids concentrations drinking-water advisory taste threshold of 60 mg/L (table 8). ranged from 62 to 173 mg/L with a median of 165 mg/L for The concentration of chloride in one sample from a sand- sand-and-gravel wells and 89 mg/L for bedrock wells. and-gravel well (J1736, 304 mg/L) and one sample from a In the Genesee River Basin, the anions detected with bedrock well (ST2065, 1,160 mg/L) exceeded the EPA SDWS the highest concentrations were bicarbonate (median of and the NYSDOH MCL of 250 mg/L. The concentration 199 mg/L in sand-and-gravel wells, 317 mg/L in bedrock of sulfate in one sample from a bedrock well (ST2065, wells), and chloride (median of 38.7 mg/L in sand-and-gravel 783 mg/L) exceeded the EPA SDWS and the NYSDOH MCL wells, 63.4 mg/L in bedrock wells) (table 7 and appendix of 250 mg/L. The concentrations of fluoride did not exceed table 1.3). The cations detected in the highest concentrations established MCLs or SDWS in any sample (table 8 and were calcium (median of 56.9 mg/L in sand-and-gravel wells, appendix table 1.3). 67.6 mg/L in bedrock wells) and sodium (median of 19.9 mg/L For samples in the St. Lawrence River Basin, 3 samples in sand-and-gravel wells, 72.4 mg/L in bedrock wells). The were classified as “soft,” 4 samples as “moderately hard,” concentration of sodium in one sample from a sand-and-gravel 3 as “hard,” and 11 samples as “very hard.” The median well (AG1129, 104 mg/L) and six samples from bedrock wells hardness was 111 mg/L as CaCO3 for sand-and-gravel wells

(AG 275, 72.4 mg/L; GS 289, 174 mg/L; LV1351, 92.5 mg/L; and 280 mg/L as CaCO3 for bedrock wells; and the maximum

MO1855, 85.0 mg/L; OT2282, 446 mg/L; and WO1483, hardness was 1,380 mg/L as CaCO3. Alkalinity ranged

69.8 mg/L) exceeded the EPA drinking-water advisory taste from 30 to 383 mg/L as CaCO3; the median was 98 mg/L as threshold of 60 mg/L (U.S. Environmental Protection Agency, CaCO3 for sand-and-gravel wells and 183 mg/L as CaCO3 2012). The concentration of chloride in one sample from a for bedrock wells. Dissolved solids concentrations ranged bedrock well (OT2282, 323 mg/L) exceeded the EPA SDWS from 71 to 3,210 mg/L with a median of 132 mg/L for sand- and the NYSDOH MCL of 250 mg/L (U.S. Environmental and-gravel wells and 388 mg/L for bedrock wells. Dissolved Protection Agency, 2012; New York State Department of solids concentration in one sample from a sand-and-gravel Health, 2011). The concentrations of fluoride and sulfate did well (J1736, 899 mg/L) and four samples from bedrock wells Groundwater Quality 25 - 0.91 13.6 28.6

mum 312 145 514 467 783 383 Maxi

1,160 1,380 3,210 - 3.6 0.39 , calcium 71.8 22.7 23.4 22.4 10.6 37.8 Me dian 3 224 280 183 388 (14 samples) Bedrock aquifers - 2.7 0.46 1.45 0.5 0.06 7.61 4.29 mum 12.8 43 46 36 86 Mini -

4.15 0.4 32.2 22.6 49.9 mum Maxi 114 168 355 304 417 292 899 St. Lawrence River Basin 9.33 0.82 4.17 5.82 0.08 7.74 11.4 28.0 98 111 118 132 Median (7 samples) - 3.2 0.67 2.58 0.48 0.04 8.78 2.73 Sand-and-gravel aquifers mum 10.1 37 38.5 30 71 Mini - 4.04 0.32 94.2 63.6 16.9 51.6

mum 446 706 323 493 580 Maxi 1,280 - 2.66 0.2 11.6 11.9 67.6 15.6 72.4 63.4 Me dian 317 221 244 456 (9 samples) Bedrock aquifers - 7.06 1.84 2.56 0.09 5.91 mum 11.6 22.9 86.2 Mini <0.20 178 147 265 -

2.2 0.2 88.8 18 82.6 14.9 26.2 mum 104 386 292 317 467 Maxi Genesee River Basin values exceed one or more drinking-water safety standards. °C, degree Celsius; CaCO 1.50 0.085 7.225 Bold 56.9 14.1 19.9 38.7 15.45 Median 199 206 165 244 (6 samples) - 6.5 0.77 7.27 0.05 6.11 0.05 mum 21.9 57 16.8 81.5 59 Mini Sand-and-gravel aquifers 159 - 6.94 8.05 0.11 9.68

23.6 22 80 35.2 12.8 87.4 22 mum Maxi 134 3.46 0.97 8.22 9.21 0.06 6.39 6.17 8.22 12.3 50 41.2 89 Median (7 samples) - Bedrock aquifers 3.88 1.34 0.48 2.65 8 0.56 0.01 5.32 4.31 2.65 mum 23.9 62 Mini -

6.9 2.17 0.06 6.85 9.05 mum 18.5 26.4 37 65.2 74.6 26.4 Maxi 173 Delaware River Basin 2.63 1.68 0.04 3.79 5.64 16.0 21.4 36 54.6 50.7 21.4 165 Median (3 samples) - 2.27 0.72 0.03 3.59 5.57 Sand-and-gravel aquifers mum 12.5 10.8 15 18.1 40.6 10.8 89 Mini 3

Summary statistics for concentrations of major ions, hardness, alkalinity, and dissolved solids in groundwater samples collected the Delaware, Genesee, Summary statistics for concentrations of major ions, hardness, alkalinity,

Calcium Magnesium Potassium Sodium Bicarbonate Chloride Fluoride Silica Sulfate

Anions Constituent Cations CaCO dried at 180 °C Hardness as CaCO Alkalinity as Dissolved solids, Table 7. Table 2015. St. Lawrence River Basins, New York, [All concentrations are in milligrams per liter filtered water representing dissolved concentrations. carbonate] 26 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 8. Drinking-water standards for concentrations of major ions and dissolved solids and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

[All concentrations are in milligrams per liter in filtered water representing dissolved concentrations; °C, degree Celsius]

Drinking- Number of samples exceeding drinking-water standards Constituent water All samples Delaware River Basin Genesee River Basin St. Lawrence River Basin standard (46 samples) (10 samples) (15 samples) (21 samples)

Sodium 460 10 0 7 3 Cations Chloride 2,3250 3 0 1 2 14.0 0 0 0 0 Fluoride 22.2 0 0 0 0 Anions 32 0 0 0 0 Sulfate 2,3250 1 0 0 1 Dissolved solids, dried at 180 °C 3500 8 0 3 5 1U.S. Environmental Protection Agency (2012) maximum contaminant level. 2New York State Department of Health (2011) maximum contaminant level. 3U.S. Environmental Protection Agency (2012) secondary drinking water standard. 4U.S. Environmental Protection Agency (2012) drinking water advisory taste threshold.

(J1628, 750 mg/L; J2146, 561 mg/L; ST2065, 3,210 mg/L; (U.S. Environmental Protection Agency, 2012; New York State ST3358, 727 mg/L) exceeded the EPA SDWS for total Department of Health, 2011) in any sample. Orthophosphate dissolved solids of 500 mg/L (table 8 and appendix table 1.3). concentrations ranged from <0.004 to 0.032 mg/L as phosphorus (P). Total organic carbon was not detected in any of the 10 samples. Nutrients and Total Organic Carbon The dominant nutrient detected in the Genesee River Basin was ammonia (table 9 and appendix table 1.4). The Groundwater samples were analyzed for several nutri- concentration of ammonia ranged from <0.01 to V7.49 mg/L ents, including ammonia plus organic nitrogen, ammonia, as N and was generally greater in samples from bedrock wells nitrate plus nitrite, nitrite, and orthophosphate, as well as (median V0.65 mg/L as N) than in samples from sand-and- for total organic carbon (unfiltered). Nitrate was calculated gravel wells (median V0.075 mg/L as N). The concentration by subtracting the nitrite from the nitrate plus nitrite mea- of nitrate and nitrate plus nitrite did not exceed the EPA and sured values. Results are reported in table 9 and in appendix NYSDOH MCL of 10 mg/L as N in any sample (table 10 and table 1.4. The numbers of samples that exceeded drinking- appendix table 1.4); however, a sample from one bedrock well water standards for nitrate, nitrite, and nitrate plus nitrite are (MO1855) had a concentration of 9.68 mg/L of N for both the reported in table 10. No drinking-water standards exist for nitrate and the nitrate plus nitrite analyses. Nitrite was detected ammonia, orthophosphate, and total organic carbon. in 3 of the 15 samples and did not exceed the NYSDOH and The dominant nutrient detected in the Delaware River EPA MCL of 1 mg/L as N in any sample. Orthophosphate Basin was nitrate (table 9 and appendix table 1.4). The concentrations ranged from <0.004 to 1.29 mg/L as P. Total concentrations of nitrate ranged from <0.040 to 2.15 mg/L organic carbon was detected in 8 of the 15 samples; the maxi- as nitrogen (N) and were generally greater in samples from mum concentration was 5.2 mg/L. sand-and-gravel wells (median 1.76 mg/L as N) than in The dominant nutrient detected in the St. Lawrence samples from bedrock wells (median 0.312 mg/L as N). River Basin was nitrate (table 9 and appendix table 1.4). The The concentrations of nitrate and nitrate plus nitrite did concentrations of nitrate ranged from <0.040 to 15.6 mg/L not exceed the EPA and NYSDOH MCL of 10 mg/L as N as N and were generally greater in samples from sand-and- (U.S. Environmental Protection Agency, 2012; New York gravel wells (median 0.103 mg/L as N) than in samples from State Department of Health, 2011) in any sample (table 10 bedrock wells (median <0.040 mg/L as N). The concentra- and appendix table 1.4). The concentrations of ammonia tions of nitrate and nitrate plus nitrite exceeded the EPA ranged from <0.010 to V0.06 mg/L as nitrogen (N) and were and NYSDOH MCL of 10 mg/L as N in one sample from a similar in samples from sand-and-gravel wells and bedrock bedrock well (ST3358; 15.6 mg/L as N) (table 10 and appen- wells. Nitrite was detected in only 1 of 10 samples and did dix table 1.4). The concentrations of ammonia ranged from not exceed the EPA and NYSDOH MCL of 1 mg/L as N <0.01 to V0.44 mg/L as N and were similar in samples from Groundwater Quality 27 -

0.004 0.026 1.8

mum 15.6 15.6 Maxi V0.53 V0.44 0.007 <0.040 <0.040 <0.001 <0.7 V0.1 V0.06 Median (14 samples) Bedrock aquifers - mum Mini <0.07 <0.01 <0.040 <0.039 <0.001 <0.004 <0.7 -

1.59 1.59 0.471 2.3 mum Maxi <0.001 V0.52 V0.42 St. Lawrence River Basin 0.103 0.103 0.006 <0.07 <0.01 <0.001 <0.7 Median (7 samples) fected by contamination. N, nitrogen; P, phosphorus; fected by contamination. N, nitrogen; P, - Sand-and-gravel aquifers mum Mini <0.07 <0.01 <0.040 <0.040 <0.001 <0.004 <0.7 - 9.68 9.68 0.043 1.29 5.2 mum

Maxi V8.4 V7.49 0.01 1.1 <0.040 <0.040 <0.001 V0.62 V0.65 Median (9 samples) Bedrock aquifers - mum Mini <0.07 <0.01 <0.040 <0.040 <0.001 <0.004 <0.7 -

1.66 1.66 0.001 0.161 1.7 mum Maxi V1.8 V1.81 Genesee River Basin 0.0235 <0.040 <0.040 <0.001 <0.7 Median V0.17 V0.075 (6 samples) - Sand-and-gravel aquifers mum Mini <0.07 <0.01 <0.040 <0.039 <0.001 <0.004 <0.7 - 0.672 0.672 0.032

mum Maxi <0.07 <0.001 <0.7 V0.06 0.312 0.312 0.008 <0.07 <0.01 <0.001 <0.7 Median (7 samples) Bedrock aquifers - mum Mini <0.07 <0.01 <0.040 <0.04 <0.001 <0.004 <0.7 -

2.15 2.15 0.001 0.018 mum Maxi <0.7 V0.07 V0.01 Delaware River Basin 1.76 1.76 0.01 <0.07 <0.01 <0.001 <0.7 Median (3 samples) - 0.301 0.301 0.008 Sand-and-gravel aquifers mum Mini <0.07 <0.01 <0.001 <0.7 ), ), 3 2 River Basins, New York, 2015. Summary statistics for concentrations of nutrients in groundwater samples collected the Delaware, Genesee, and St. Lawrence River Basins, New York,

+ + ), as N ), as P 3 3 + ), as N 4 4 2 organic N, organic as N (NH NH nitrite (NO NO as N as N phate (PO carbon, unfiltered Constituent Ammonia plus Ammonia Ammonia Nitrate plus Nitrate (NO Nitrite (NO Orthophos organic Total Table 9. Table [All concentrations are in milligrams per liter and filtered water unless otherwise indicated as unfiltered. “V” remark codes indicate that a value may be af <, less than] 28 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 10. Drinking-water standards for concentrations of nutrients and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

[All concentrations in milligrams per liter in filtered water. N, nitrogen]

1,2 Nitrate (NO3), as N 10 1 0 0 1 1,2 Nitrite (NO2), as N 1 0 0 0 0 1U.S. Environmental Protection Agency (2012) maximum contaminant level. 2New York State Department of Health (2011) maximum contaminant level. sand-and-gravel wells and bedrock wells. Nitrite was detected Department of Health, 2011). The maximum concentration of in only 4 of 21 samples and did not exceed the EPA and manganese was 225 µg/L in a filtered sample from bedrock NYSDOH MCL of 1 mg/L as N in any sample. Orthophos- well O10369. A sample from one bedrock well (SV1689) had phate concentrations ranged from <0.004 to 0.471 mg/L as P. a concentration of aluminum that exceeded the EPA SDWS of Total organic carbon was detected in 5 of the 21 samples; the 50–200 µg/L (U.S. Environmental Protection Agency, 2012). maximum concentration was 2.3 mg/L. Drinking-water standards for antimony, arsenic, barium, beryllium, boron, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, silver, strontium, thallium, Trace Elements zinc, and uranium were not exceeded (table 12 and appendix table 1.5). Antimony, chromium, mercury, silver, and Twenty-five trace elements were analyzed for in fil- thallium were not detected in any of the 10 Delaware River tered and (or) unfiltered groundwater samples. Mercury was Basin samples collected (tables 11 and 12; appendix tables 1.1 not detected in groundwater samples from any of the basins and 1.5). (appendix table 1.1). Results are reported in table 11 and in In the Genesee River Basin, the trace elements pres- appendix table 1.5. The numbers of samples that exceeded ent in the highest median concentrations in the samples were drinking-water standards for trace elements are reported strontium (median of 516 µg/L in bedrock wells, 170 µg/L in in table 12. No drinking-water standards exist for cobalt sand-and-gravel wells), iron (median of 522 µg/L in unfil- and lithium. tered water from bedrock wells, 454 µg/L in filtered water In the Delaware River Basin, the trace elements present from sand-and-gravel wells), barium (median of 260 µg/L in in the highest median concentrations in the samples were bedrock wells, 240 µg/L in sand-and-gravel wells), manganese strontium (median of 78.4 micrograms per liter [µg/L] in sand- (median of 77.8 µg/L in unfiltered water from bedrock wells, and-gravel wells, 111 µg/L in bedrock wells), iron (median of 62.1 µg/L in unfiltered water from sand-and-gravel wells), 47.1 µg/L in unfiltered water from bedrock wells, 20.5 µg/L and boron (median of 243 µg/L in filtered water from bedrock in filtered water from bedrock wells), and boron (median wells, 24 µg/L in filtered water from sand-and-gravel wells) of 11 µg/L in filtered water from bedrock wells, 11 µg/L (table 11 and appendix table 1.5). in filtered water from sand-and-gravel wells) (table 11 and In the Genesee River Basin, the concentration of alumi- appendix table 1.5). num in three samples from bedrock wells (AG2300, 207 µg/L; In the Delaware River Basin, the concentrations of OT2282, 365 µg/L; WO1483, 461 µg/L) exceeded the EPA iron in one sample from a bedrock well (O10369) exceeded SDWS of 50–200 µg/L (table 12 and appendix table 1.5) in the NYSDOH MCL and EPA SDWS of 300 µg/L (New the Genesee River Basin. The concentration of arsenic in York State Department of Health, 2011; U.S. Environmen- two samples—one from bedrock well (LV1351, 44.0 µg/L), tal Protection Agency, 2012) in the filtered and unfiltered and one from sand-and-gravel well (AG1129, 161 µg/L)— samples (8,190 µg/L in the filtered sample; 7,760 µg/L in the exceeded the EPA MCL and NYSDOH MCL of 10 µg/L unfiltered sample) (table 12 and appendix table 1.5). Another (U.S. Environmental Protection Agency, 2012; New York sample from a bedrock well (D2321) exceeded the NYSDOH State Department of Health, 2011). The concentration of iron MCL and EPA SDWS for iron in only the unfiltered sample in nine samples (five bedrock wells and four sand-and-gravel) (412 µg/L). Samples from two bedrock wells (D2321 and exceeded the NYSDOH MCL and EPA SDWS of 300 µg/L O10369) and one sand-and-gravel well (SV 39) had concentra- in unfiltered samples; the maximum iron concentration was tions of manganese that exceeded the EPA SDWS of 50 µg/L 2,200 µg/L (OT2282). Seven of the nine samples also had con- (U.S. Environmental Protection Agency, 2012) in unfiltered centrations of iron that exceeded the MCL and SDWS when and filtered samples. However, samples from these wells did filtered. The concentration of manganese in 9 of 15 samples not exceed the NYSDOH MCL of 300 µg/L (New York State from the Genesee River Basin (5 from bedrock wells, 4 from Groundwater Quality 29 7.3 0.72 3 0.03 0.055 0.74 0.25 7.8 1.29 7.86 1.1 0.292 3.06 83.8 13.9 <0.030 <0.12 372 568 563 442 225

1,430 Maximum 22,600 0.76 0.06 8.08 8.12 8.5 1.44 4.6 0.608 48.2 52 92.6 <3.8 <0.18 <0.02 <0.030 <0.40 <0.05 <1.0 <0.20 <0.100 <0.030 <0.06 124 Median (14 samples) 1,030 Bedrock aquifers - 4.6 0.62 0.13 mum Mini 96.5 <3.8 <0.18 <0.20 <0.25 <0.02 <0.030 <0.40 <0.05 <0.80 <4.0 <4.6 <0.04 <0.20 <0.4 <0.20 <0.100 <0.030 <0.06 <2.0 <0.028

0.62 0.03 0.067 1.7 0.37 0.68 2.27 1.3 0.137 0.035 0.1 0.689 20.6 20.5 15.8 <0.18 St. Lawrence River Basin 189 129 178 167 253 225 225 Maximum 4,990 5.8 0.51 7.3 0.1 1.7 0.24 0.88 2.48 7.1 0.55 4.1 0.249 40.5 13.1 91.7 62.9 <0.18 <0.02 <0.030 <0.40 <0.20 <0.100 <0.030 <0.06 Median (7 samples) Sand-and-gravel aquifers 4.81 3.4 0.7 0.13 0.045 28.5 <3.8 <0.18 <0.20 <0.02 <0.030 <0.40 <0.05 <0.80 <4.0 <4.6 <0.04 <0.20 <0.4 <0.20 <0.100 <0.030 <0.06 <2.0 Minimum 0.75 0.03 0.194 8.6 0.57 2.87 3.56 4.5 0.224 0.07 0.726 44 32.9 <0.060 118 461 454 656 171 449

1,170 1,500 2,200 3,570 Maximum 0.28 0.06 0.28 0.32 0.97 6.6 0.033 10 36.7 37.9 77.8 <0.18 <0.02 <0.030 <0.40 <0.80 <0.100 <0.030 <0.06 260 243 153 522 516 Median (9 samples) Bedrock aquifers - 6 0.05 0.87 0.95 1 0.11 mum 23 33 <3.8 <0.18 <0.20 <0.02 <0.030 <0.40 <0.05 <0.80 <4.0 <0.20 <0.100 <0.030 <0.06 <2.0 <0.014 Mini 188 values exceed one or more drinking-water safety standard. <, less than.]

Bold . 9.7 0.039 0.1 3.8 1.88 7.56 1.9 0.147 0.339 Genesee River Basin 90 13.8 64.8 <0.18 <0.02 <0.40 <0.030 <0.06 161 733 257 270 519 Maximum 1,720 1,680 4.1 2.2 2.1 0.45 4.115 0.92 0.72 6.8 0.052 24 57.1 62.1 <0.18 <0.02 <0.030 <0.40 <0.05 <0.100 <0.030 <0.06 240 454 448 170 Median (6 samples) - Sand-and-gravel aquifers 0.26 2.95 9.3 7.9 mum 62.1 15 Mini <3.8 <0.18 <0.02 <0.030 <0.40 <0.05 <0.80 <0.04 <0.20 <0.4 <0.05 <0.20 <0.100 <0.030 <0.06 <2.0 <0.014 109 6.2 6.2 1.1 0.107 6.3 0.79 0.3 6.8 0.126 1.16

55.8 35 33 70.2 17 <0.18 <0.40 <0.030 <0.06 225 213 689 Maximum 8,190 7,760 1.2 1.2 4.7 0.25 8.38 3.18 0.15 8.5 0.511 11 15.4 20.5 47.1 <0.18 <0.02 <0.030 <0.40 <0.05 <0.20 <0.100 <0.030 <0.06 V9.2 111 Median (7 samples) Bedrock aquifers - 3.8 0.38 0.38 5.8 0.15 0.83 2.1 0.063 mum Mini 34.6 19.2 <0.18 <0.02 <0.030 <0.40 <0.05 <0.80 <4.0 <0.20 <0.05 <0.20 <0.100 <0.030 <0.06 V0.5

0.37 0.37 0.04 0.036 1.78 4.07 2.1 0.17 0.031 11 11.7 17.9 37.5 68.5 85.6 90.4 93.4 <0.18 <0.40 <0.05 <0.05 <0.030 <0.06 101 Delaware River Basin Maximum 0.22 0.22 0.96 0.24 0.41 6.3 2.2 11 12.7 21.6 78.4 <3.8 <0.18 <0.02 <0.030 <0.40 <0.05 <0.05 <0.20 <0.100 <0.030 <0.06 <0.014 V7 Median (3 samples) - 6 0.06 0.36 4.99 Sand-and-gravel aquifers mum 11.8 17.2 47.7 Mini <3.8 <0.18 <0.02 <0.02 <0.02 <0.030 <0.40 <0.05 <0.80 <0.05 <0.20 <0.100 <0.030 <0.06 <2.0 <0.014 V5.2 er Basins, New York, 2015. Summary statistics for concentrations of trace elements in groundwater collected the Delaware, Genesee, and St. Lawrence Riv er Basins, New York, - filtered filtered num Constituent Aluminum Antimony Arsenic Barium Beryllium Boron, Cadmium Chromium Cobalt Copper Iron, filtered Iron Lead Lithium Manganese, Manganese Molybde Nickel Selenium Silver Strontium Thallium Zinc Uranium Table 11. Table [All concentrations in micrograms per liter unfiltered water unless otherwise indicated as filtered 30 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 12. Drinking-water standards for concentrations of trace elements and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

[All concentrations in micrograms per liter in unfiltered water representing unless otherwise indicated as filtered water]

Number of samples exceeding drinking-water standards Drinking-water Constituent standard All samples Delaware River Basin Genesee River Basin St. Lawrence River Basin (46 samples) (10 samples) (15 samples) (21 samples) Aluminum 350–200 4 1 3 0 Antimony 1,26 0 0 0 0 Arsenic 1,210 2 0 2 0 Barium 1,22,000 0 0 0 0 Beryllium 1,24 0 0 0 0 Boron 56,000 0 0 0 0 63,000 0 0 0 0 Cadmium 1,25 0 0 0 0 Chromium 1,2100 0 0 0 0 Copper 31,000 0 0 0 0 Iron, filtered 2,3300 10 1 7 2 Iron 2,3300 13 2 9 2 Lead 415 0 0 0 0 Manganese, filtered 2300 0 0 0 0 350 14 3 7 4 Manganese 2300 1 0 1 0 350 16 3 9 4 Molybdenum 540 0 0 0 0 680 0 0 0 0 Nickel 5100 0 0 0 0 61,000 0 0 0 0 Selenium 1,250 0 0 0 0 Silver 2,3100 0 0 0 0 Strontium 54,000 4 0 0 4 625,000 0 0 0 0 Thallium 1,22 0 0 0 0 Zinc 2,35,000 0 0 0 0 Uranium 1,230 0 0 0 0 1U.S. Environmental Protection Agency (2012) maximum contaminant level. 2New York State Department of Health (2011) maximum contaminant level. 3U.S. Environmental Protection Agency (2012) secondary drinking water standard. 4U.S. Environmental Protection Agency (2012) treatment technique. 5U.S. Environmental Protection Agency (2012) lifetime health advisory. 6U.S. Environmental Protection Agency (2012) single-day health advisory. Groundwater Quality 31 sand-and-gravel wells) exceeded the EPA SDWS of 50 µg/L detected were broadleaf herbicides or their degradates. Two in unfiltered samples; only 3 of the samples from those 9 wells of the wells with pesticide detections were sand-and-gravel did not have an exceedance in the associated filtered sample. production wells (D 276 and SV 534), and one well was a The concentration of manganese in one of these samples bedrock production well (D 199). The pesticide atrazine was further exceeded the NYSDOH MCL of 300 µg/L. The detected in two samples (D 276 and SV 534). The pesticide maximum manganese concentration was 449 µg/L (AG2300). prometon was detected in one sample (D 199). The pesticide Drinking-water standards for antimony, beryllium, cadmium, degradate 2-chloro-4-isopropylamino-6-amino-S-triazine chromium, copper, lead, mercury, selenium, silver, thallium, (deethylatrazine [CIAT], a degradation product of atrazine) and zinc were not exceeded. Silver was not detected in any of was detected at the highest concentration (E0.040 µg/L). the 15 Genesee River Basin samples collected (tables 11 and In the Genesee River Basin, three broadleaf herbicides 12; appendix tables 1.1 and 1.5). and a degradate were detected at trace concentrations among In the St. Lawrence River Basin, the trace elements pres- three samples. CIAT was detected in a sand-and-gravel pro- ent in the highest median concentrations in the samples were duction well (AG 266). Two domestic bedrock wells (LV1423 strontium (median of 62.9 µg/L in sand-and-gravel wells, and MO1855) had trace concentrations of CIAT, atrazine, 1,030 µg/L in bedrock wells), iron (median of 92.6 µg/L in metolachlor, and prometon. The pesticide degradate CIAT was unfiltered water from bedrock wells, 91.7 µg/L in unfiltered detected at the highest concentration (E0.039 µg/L). water from sand-and-gravel wells), and boron (median of In the St. Lawrence River Basin, two broadleaf herbicides 124 µg/L in filtered water from bedrock wells, 7.3 µg/L in fil- and a degradate were detected at trace concentrations in two tered water from sand-and-gravel wells) (table 11 and appen- samples. CIAT was detected in one sand-and-gravel produc- dix table 1.5). tion well (ST 366). Metolachlor and prometon were detected In the St. Lawrence River Basin, the concentration of in one sand-and-gravel well (F 543). Both metolachlor and iron in samples from two bedrock wells (ST2227 and ST3674) prometon were detected at the highest concentration (both at exceeded the NYSDOH MCL and EPA SDWS of 300 µg/L 0.036 µg/L). in filtered and unfiltered samples (table 12); the maximum iron concentration was 568 µg/L (ST3674). The concentration of manganese in samples from two sand-and-gravel wells Volatile Organic Compounds (F1544 and J1736) and two bedrock wells (J2146 and Groundwater samples were analyzed for 34 VOCs. Of ST2227) exceeded the EPA SDWS of 50 µg/L in unfiltered the 34 VOCs analyzed, 29 were not detected in any samples samples. None of the samples from these four wells further from any of the basins (table 1.1). For the five VOCs detected exceeded the NYSDOH MCL of 300 µg/L for manganese. The in samples, drinking-water standards only exist for two of maximum manganese concentration was 225 µg/L (F1544). these VOCs, and no concentrations exceeded established The EPA does currently have a lifetime health advisory of drinking-water standards set for VOCs. Results are reported in 4,000 µg/L and a single-day health advisory of 25,000 µg/L appendix table 1.7. for strontium (U.S. Environmental Protection Agency, 2012). In the Delaware River Basin, one VOC, a trihalomethane One sand-and-gravel well (J1736, 4,990 µg/L) and three (THM) or byproduct formed when chlorine or bromine are bedrock wells in the St. Lawrence River Basin exceeded the used as disinfectants, was detected in a sample from one sand- lifetime health advisory for strontium (J1628, 14,200 µg/L; and-gravel production well (D 276) (appendix table 1.7). The J2146, 7,020 µg/L; ST2065, 22,600 µg/L). Drinking-water VOC detected was the THM trichloromethane, or chloroform standards for aluminum, antimony, arsenic, beryllium, (0.6 µg/L). cadmium, chromium, copper, lead, mercury, selenium, silver, In the Genesee River Basin, four VOCs were detected thallium, and zinc were not exceeded (tables 11 and 12; among samples from two bedrock wells (LV1351 and appendix tables 1.1 and 1.5). MO1855) (appendix table 1.7). The VOCs detected included two THMs—trichloromethane and bromodichlorometh- Pesticides ane—and two solvents—1,1,1-trichloroethane and toluene. The sample from bedrock well MO1855 contained detectable Groundwater samples were analyzed for 52 pesticides concentrations of three VOCs: 1,1,1-trichloroethane, bromodi- and pesticide degradates. Of the 52 pesticides and pesticide chloromethane, and trichloromethane. The VOC detected at degradates analyzed for, 48 were not detected in any samples the highest concentration, 0.8 µg/L was trichloromethane, in a from any of the basins (table 1.1). For the four pesticides sample from a bedrock well (MO1855). and pesticide degradates detected in groundwater samples In the St. Lawrence River Basin, three VOCs were (table 1.6), no concentrations exceeded established drinking- detected in one sample from a sand-and-gravel production water standards set for pesticides and pesticide degradates. well (ST 378) (appendix table 1.7). The VOCs detected were In the Delaware River Basin, two pesticides and one three THMs—bromodichloromethane, dibromochlorometh- pesticide degradate were detected at trace concentrations ane, and trichloromethane. Trichloromethane was detected at among three samples (appendix table 1.6). All of the pesticides the highest concentration (0.7 µg/L). 32 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Radionuclides and EPA MCLs of 15 pCi/L for gross-α activity. Gross-β activities ranged from nondetectable levels to 7.7 pCi/L. Groundwater samples were analyzed for radon-222, Radon-222 activities in the groundwater samples ranged gross-α activity and gross-β activity. Radon is currently from nondetectable levels to 1,280 pCi/L; the medians were (2019) not regulated in drinking water; however, the EPA 400 pCi/L in sand-and-gravel wells and 410 in bedrock has proposed a two-part standard for radon-222 in drinking wells. The highest radon-222 activity was in a sample from water: (1) a 300-picocuries per liter (pCi/L) MCL for areas a bedrock well (J1451, 1,280 pCi/L). Radon-222 activities that do not implement an indoor-air radon-222 mitigation in 14 of the 21 St. Lawrence River Basin samples exceeded program and (2) an alternative MCL (AMCL) of 4,000 pCi/L the proposed MCL of 300 pCi/L; no samples exceeded the for areas that do implement an indoor-air radon-222 mitigation proposed AMCL of 4,000 pCi/L (table 14 and appendix program (U.S. Environmental Protection Agency, 1999). table 1.8). The EPA and NYSDOH MCLs for gross-α activity are 15 pCi/L (U.S. Environmental Protection Agency, 2012; New York State Department of Health, 2011). The EPA and Bacteria NYSDOH MCLs for gross-β are 4 millirems per year (U.S. Groundwater samples were analyzed for fecal indicator Environmental Protection Agency, 2012; New York State Department of Health, 2011), a dosage determination that bacteria, including E. coli bacteria, fecal coliform bacteria, requires knowledge of the specific radionuclide sources. The and total coliform bacteria. Heterotrophic plate count was activity units (picocuries per liter) that were used to measure also determined. Heterotrophic plate count is used to assess gross-β radioactivity in this study are not comparable to the overall bacterial load in the sample, which in conjunction dosage units (millirems per year) without determination of with fecal indicator bacteria allows for inferring potential the nuclide sources; therefore, it is not possible to determine sources of contamination. The NYSDOH and EPA MCLs whether any of the samples exceeded the MCL for gross-β for total coliform bacteria are exceeded when 5 percent of radioactivity. Results are reported in appendix table 1.8. samples of finished water collected in 1 month test positive In the Delaware River Basin, gross-α activity ranged for total coliforms (if 40 or more samples are collected per from nondetectable levels to 4.0 pCi/L (table 13 and appen- month) or when two samples of finished water test positive dix table 1.8). No samples exceeded the NYSDOH and EPA for total coliforms (if fewer than 40 samples are collected per MCLs of 15 pCi/L for gross-α activity (table 14 and appen- month) (U.S. Environmental Protection Agency, 2012; New dix table 1.8). Gross-β activities ranged from nondetect- York State Department of Health, 2011). In this report, where able levels to 13.0 pCi/L. Radon-222 activities in the water conditions are based on one sample per well, any detection samples ranged from 310 to 2,190 pCi/L; the median activity of total coliform bacteria, fecal coliform bacteria, or E. coli was 750 pCi/L for sand-and-gravel wells and 980 pCi/L for bacteria is described as an exceedance. Units for total coliform bedrock wells. The highest radon-222 activities were in a bacteria, fecal coliform bacteria, and E. coli bacteria results sample from one bedrock well, SV 132 (2,190 pCi/L), that is are in colony-forming units per 100 milliliters (CFU/100 mL); completed in shale and sandstone bedrock. Radon-222 activi- units for heterotrophic plate count are in colony-forming units ties in all 10 of the Delaware River Basin samples exceeded per milliliter (CFU/mL). Results are reported in appendix the proposed MCL of 300 pCi/L; no samples exceeded the table 1.9. proposed AMCL of 4,000 pCi/L (table 14). In the Delaware River Basin, total coliform bacteria In the Genesee River Basin, gross-α activity ranged were detected in two samples from bedrock wells (D1584, from nondetectable levels to 4.9 pCi/L (table 13 and appendix 11 CFU/100 mL; D1997, 1 CFU/100 mL) (appendix table 1.8). No samples exceeded the NYSDOH and EPA table 1.9), therefore exceeding the EPA and NYSDOH MCLs. MCLs of 15 pCi/L for gross-α activity. Gross-β activities Fecal coliform bacteria and E. coli bacteria were not detected ranged from nondetectable levels to 10.6 pCi/L. Radon-222 in samples from any wells. The heterotrophic plate count activities in the groundwater samples ranged from 260 to ranged from <1 to 24 CFU/mL; no Delaware River Basin 1,440 pCi/L; the medians were 515 pCi/L in sand-and-gravel samples exceeded the EPA MCL for heterotrophic plate count wells and 330 pCi/L in bedrock wells. The two highest radon- (EPA MCL is 500 CFU/mL; U.S. Environmental Protection 222 activities were in samples from bedrock wells completed Agency, 2012). in shale and sandstone (AG2300, 1,440 pCi/L; LV1423, In the Genesee River Basin, total coliform bacteria were 1,010 pCi/L). Radon-222 activities in 12 of the 15 Genesee detected in six samples from bedrock wells (AG 275, GS 289, River Basin samples exceeded the proposed MCL of LV1423, MO1855, OT2282, and WO1483), all exceeding 300 pCi/L with one additional sample with an activity equal to the EPA and NYSDOH MCLs for total coliform bacteria the proposed MCL; no samples exceeded the proposed AMCL (appendix table 1.9). The maximum detection of total coliform of 4,000 pCi/L (table 14 and appendix table 1.8). bacteria was >200 CFU/100 mL (LV1423). Fecal coliforms In the St. Lawrence River Basin, gross-α activity (130 CFU/100 mL) and E. coli bacteria (178 CFU/100 mL) ranged from nondetectable levels to 8.9 pCi/L (table 13 and were also detected in well LV1423. Well LV1423 exceeded appendix table 1.8). No samples exceeded the NYSDOH the EPA and NYSDOH MCLs for fecal coliform bacteria and Groundwater Quality 33 - 8.9 7.7 mum Maxi 1,280 1.2 3.6 410 Median (14 samples)

Bedrock aquifers <0.65 <0.89 Mini mum <11.2 - 0.8 4 mum 870 Maxi St. Lawrence River Basin 1.4 <1.0 400 Median (7 samples)

Mini mum 65 <0.65 <0.87 Sand-and-gravel aquifers - 4.9 10.6 mum Maxi 1,440 1.7 4.6 330 Median (9 samples) - Bedrock aquifers 2.7 <1.3 260 mum Mini - 2.6 5.8 mum 880 Maxi Genesee River Basin 1 2.6 515 Median (6 samples) - <0.58 <1.1 mum Mini 270 Sand-and-gravel aquifers values exceed one or more proposed drinking-water safety standard. gross-α, gross-alpha; gross-β, gross-beta <, less than] - 4.0 13.0 mum Maxi 2,190 1.0 1.5 980 Median Bold and italicized (7 samples) . - Bedrock aquifers <0.63 <0.75 mum Mini 310

0.7 2.8 mum Maxi 1,260 Delaware River Basin <1.2 <1.4 750 Median (3 samples) - <0.83 <1.3 mum Sand-and-gravel aquifers Mini 410 River Basins, New York, 2015. Summary statistics for activities of radionuclides in groundwater samples collected the Delaware, Genesee, and St. Lawrence River Basins, New York,

radioactivity radioactivity Constituent Gross-α Gross-β Radon-222 Table 13. Table [All activities in picocuries per liter and are unfiltered water 34 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015

Table 14. Drinking-water standards for activities of radionuclides and number of groundwater samples exceeding those standards collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

[All activities in picocuries per liter in unfiltered water. Activity units (picocuries per liter) used to measure gross-beta (gross-β) radioactivity in this study are not comparable to dosage units (millirems per year). gross-α, gross-alpha; mrem/yr, millirem per year; --, not applicable]

Number of samples exceeding drinking-water standards Drinking-water Constituent standard All samples Delaware River Basin Genesee River Basin St. Lawrence River Basin (46 samples) (10 samples) (15 samples) (21 samples) Gross-α radioactivity 1,215 0 0 0 0 Gross-β radioactivity 1,2,4mrem/yr ------Radon-222 3300 36 10 12 14 44,000 0 0 0 0 1U.S. Environmental Protection Agency (2012) maximum contaminant level. 2New York State Department of Health (2011) maximum contaminant level. 3U.S. Environmental Protection Agency (1999) proposed maximum contaminant level. 4U.S. Environmental Protection Agency (1999) proposed alternative maximum contaminant level.

E. coli bacteria. The heterotrophic plate count ranged from substantially lower in 2015 and 2010 (<1 Pt-Co units) than <1 to 319 CFU/mL; no samples exceeded the EPA MCL for in 2005–6 (8 Pt-Co units). Concentrations of nutrients, major heterotrophic plate count. ions, dissolved gases (2010 and 2015 only), and most trace In the St. Lawrence River Basin, total coliform bacteria elements exhibited little to no change in both wells (appen- were detected in one sample from a bedrock well (ST3358, dix tables 2.1 to 2.4, 2.7). The concentrations of aluminum, 52 CFU/100 mL), therefore exceeding the EPA and NYSDOH iron (unfiltered), lead, manganese (unfiltered), nickel, stron- MCLs for total coliform bacteria (appendix table 1.9). Fecal tium, and zinc differed substantially in the SV1689 sample coliforms (2 CFU/100 mL) and E. coli bacteria (detected but from 2015, compared to previous samples from that well not quantified) were also detected in well ST3358, therefore (appendix table 2.4). The concentration of aluminum in the exceeding the EPA and NYSDOH MCLs for fecal coliform sample from SV1689 in 2015 was 55.8 µg/L, which is higher bacteria and E. coli bacteria. The heterotrophic plate count than the EPA SDWS of 50–200 µg/L but considerably lower ranged from <1 to 227 CFU/mL; no samples exceeded the than in 2005–6, when the concentration was 1,100 µg/L. The EPA MCL for heterotrophic plate count. concentrations of iron, lead, manganese, nickel, and zinc also decreased substantially from 2005–6 (appendix table 2.4). The concentration of strontium, alternatively, increased since Comparison of Results From Wells Sampled in 2005–6 and 2010 (220 µg/L in 2005–6; 276 µg/L in 2010; 2005–6, 2010, and 2015 and 489 µg/L in 2015). For well SV 534, atrazine and CIAT were detected in both the 2010 sample (CIAT—E0.077 µg/L; A subset of 10 wells sampled in 2015 were previously atrazine—E0.059 µg/L) and the 2015 sample (CIAT— sampled in 2010 and (or) 2005–6. Of the 148 physical proper- E0.040 µg/L; atrazine—0.031 µg/L) (appendix table 2.5). ties, organic compounds, and inorganic compounds analyzed No VOCs were detected in samples from either of the wells for in 2015 and 2010, 140 were also analyzed for in 2005–6. that were resampled (appendix table 2.6). Gross-α, gross-β, Note that the NWQL annually updates the LRLs for all ana- and radon-222 activities exhibited little to no change for lytes based on method performance during the previous year these wells (appendix table 2.7). Total coliform bacteria were of analysis. Therefore, reporting levels and the determination detected in the 2010 sample from SV 534 but not in the 2015 of whether a concentration is considered “estimated” changes sample (appendix table 2.8). Total coliform bacteria were annually, and concentrations of compounds could differ for detected in the 2005–6 and 2010 samples from SV1689 but this reason between 2005–6, 2010, and 2015. The rules for were not detected in 2015. In 2010, 70 CFU/100 mL of total determining and adjusting LRLs and long-term method detec- coliform was detected in SV1689, up from 3 CFU/100 mL in tion levels are outlined by the USGS Branch of Quality Sys- 2005–6. Fecal coliform bacteria and E. coli bacteria were not tems (U.S. Geological Survey, 1999a,b). Results are reported detected in any samples from either well. The heterotrophic in appendix tables 2.1 through 2.8. plate count for SV 534 was slightly higher in 2015 compared Two of the Delaware River Basin wells sampled in 2015 to 2010; however, for SV1689, the heterotrophic plate count (wells SV 534 and SV1689) were sampled previously in 2010; decreased from 86 CFU/mL in 2005–6 to 6 CFU/mL in 2010, SV1689 was sampled in 2005–6 as well. Overall, physio- to <1 CFU/mL in 2015 (appendix table 2.8). chemical properties exhibited little to no change for these Three of the Genesee River Basin wells sampled in 2015 wells (appendix table 2.1); however, for SV1689, color was (AG 266, AG1129, and WO 352) were sampled previously Summary 35 in 2010. Overall, physiochemical properties exhibited little samples from F 573, J1736, ST 366, or ST 378 (appendix table to no change for these wells (appendix table 2.1); however, 2.8). For well F 543, 3 CFU/100 mL were detected in the 2010 for AG1129, color was substantially lower in 2015 (2 Pt-Co sample only; samples from 2005–6 and 2015 were negative. units) than in 2010 (10 Pt-Co units). Concentrations of Fecal coliform bacteria and E. coli bacteria were not detected nutrients, some dissolved gases (2010 and 2015 only), major in any samples from the five resampled wells. Heterotrophic ions, and trace elements showed little change for each of the plate counts in these five wells were relatively unchanged three wells (appendix tables 2.1 to 2–4, and 2–7). Concentra- across the three rounds of sampling (appendix table 2.8). tions of carbon dioxide in samples from AG 266 and WO 352 were substantially higher in samples from 2010 (26.1 and 24.6 mg/L, respectively) than in samples from 2015 (mean of 8.0 and 10.1 mg/L, respectively). For wells AG1129 and Summary WO 352, no pesticides were detected in any of the samples from 2010 or 2015 (appendix table 2.5). For well AG 266, In a study conducted by the U.S. Geological Survey CIAT was detected in the sample from 2015 (E0.003 µg/L), (USGS), in cooperation with the New York Department of but it was not detected in the sample from 2010 (appendix Environmental Conservation, groundwater samples were table 2.5). No VOCs were detected in samples from either of collected during May through November 2015 from 10 wells the wells that were resampled (appendix table 2.6). Gross-α, in the Delaware River Basin, 15 wells in the Genesee River gross-β and radon-222 activities exhibited little to no change Basin, and 21 wells in the St. Lawrence River Basin to charac- for these wells (appendix table 2.7). Total coliform bacteria, terize the overall groundwater quality in each of these basins. fecal coliform bacteria, and E. coli bacteria were not detected Sample collection and analysis followed standard U.S. Geo- in any samples from AG 266, AG1129, or WO 352 (appen- logical Survey procedures and other documented procedures. dix table 2.8). Heterotrophic plate counts in these three wells Samples were measured for physical properties and concentra- were consistent across the two rounds of sampling (appen- tions of dissolved gases, major ions, nutrients, trace elements, dix table 2.8). pesticides, volatile organic compounds (VOCs), radionuclides, Four of the St. Lawrence River Basin wells sampled in and bacteria. About 53 percent (78 of 148) of constituents 2015 (F 543, F 573, J1736, and ST 378) were sampled previ- analyzed for were not detected at concentrations greater than ously in 2010; three of those wells (F 543, F 573, and ST 378) laboratory reporting levels in any of the samples. and one additional well (ST 366) were sampled in the 2005–6 Five of the 10 wells sampled in the Delaware River Basin round as well. Overall, physiochemical properties exhibited are production wells, and the remaining 5 are domestic wells. little to no change for these wells (appendix table 2.1); how- Samples from these wells generally had few exceedances of ever, for F 543, color decreased over time; color was 5 Pt-Co State and (or) Federal drinking-water standards, although con- units in 2005–6, 2 Pt-Co units in 2010, and <1 Pt-Co units centrations of some constituents—pH, color, aluminum, iron, in 2015. For well ST 378, dissolved oxygen was measured manganese, radon-222, and total coliform bacteria—equaled lower in 2010 (3.0 mg/L) and 2015 (3.6 mg/L) than in 2005–6 or exceeded primary, secondary, or proposed drinking-water (9.2 mg/L). Concentrations of nutrients, dissolved gases (2010 standards. Every well sampled in the Delaware River Basin and 2015 only), most major ions, and trace elements showed had at least one constituent equal to or greater than a primary, little change for each of the five wells (appendix tables 2.1 to secondary, or proposed drinking-water standard. The con- 2.4, and 2.7). Concentrations of sodium and chloride in sam- stituents most frequently detected in concentrations exceed- ples from well J1736 increased from 2010 (105 and 206 mg/L, ing drinking-water standards were manganese (filtered and respectively) to 2015 (168 and 304 mg/L, respectively). The unfiltered; 3 out of 10 samples) and pH (3 out of 10 samples). concentration of chloride in the 2015 sample from J1736 Additionally all 10 samples collected in the Delaware River exceeded the EPA SDWS and NYSDOH MCL of 250 mg/L. Basin had radon-222 activities equal to or greater than the For wells F 573 and ST 378, no pesticides were detected in U.S. Environmental Protection Agency [EPA] proposed any of the samples from 2005–6, 2010, or 2015. For well F maximum contaminant level (MCL) of 300 picocuries per liter 543, the pesticide prometon was only detected in the 2015 [pCi/L]). The highest radon-222 activities were in samples sample (0.036 µg/L). For well J1736, the pesticide degradate from wells completed in bedrock. CIAT was only detected in the 2010 sample (E0.001 µg/L). In the Delaware River Basin, pH was typically slightly For the well ST 366, CIAT was detected in both the 2005–6 below neutral. The groundwater was typically soft, although sample (E0.011 µg/L) and the 2015 sample (E0.015 µg/L) some wells were moderately hard. The median dissolved (appendix table 2.5). VOCs were not detected in any samples solids concentration was 165 milligrams per liter (mg/L) in from F 543, F 573, J1736, or ST 366. For well ST 378, three sand-and-gravel wells and 89 mg/L in bedrock wells. The ions VOCs—three THMs (trichloromethane, bromodichlorometh- detected in the highest median concentrations were bicarbon- ane, and dibromochloromethane) were detected in the 2015 ate, chloride, calcium, and sodium. The dominant nutrient was sample (appendix table 2.6). Gross-α, gross-β, and radon-222 nitrate; concentrations of nitrate and nitrite did not exceed activities exhibited little to no change for these wells (appen- established drinking-water standards. Strontium, manganese, dix table 2.7). Total coliform bacteria were not detected in iron, and boron were the trace elements with the highest 36 Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015 median concentrations. Iron concentrations exceeded drinking- had at least one constituent equal to or greater than primary, water standards in samples from two wells; the maximum secondary, or proposed standards. The constituent most fre- concentration was 8,190 micrograms per liter. Manganese quently detected in concentrations exceeding drinking-water concentrations in three samples exceeded drinking-water stan- standards was dissolved solids (5 out of 12 samples). Radon- dards. Two pesticides and a pesticide degradate were detected 222 activities were equal to or greater than the proposed EPA among three samples. One sample had a detection of a VOC MCL of 300 pCi/L for 14 out of 21 samples. The highest (trichloromethane). Radon-222 activities in all 10 samples radon-222 activities were in samples from wells completed in exceeded a proposed MCL; no samples exceeded the proposed sand and gravel. alternative maximum contaminant level. Total coliform bacte- In the St. Lawrence River Basin, sample pH was typi- ria were detected in two samples. cally near neutral. The groundwater tended toward moderately In the Genesee River Basin, 8 of the 15 wells sampled hard to very hard, and the median dissolved solids concentra- are production wells, and 7 are domestic wells. The samples tion was 132 mg/L in sand-and-gravel wells and 388 mg/L had several exceedances of State and (or) Federal drinking- in bedrock wells. The ions detected in the highest median water standards, and properties and concentrations of some concentrations were bicarbonate, sulfate, calcium, magnesium, constituents—color, sodium, dissolved solids, chloride, iron, and sodium. The dominant nutrient was nitrate; concentrations manganese, arsenic, aluminum, radon-222, methane, total of nitrate and nitrite did not exceed established drinking-water coliform bacteria, fecal coliform bacteria, and Escherichia standards. Strontium, iron, and boron were the trace elements coli (E. coli) bacteria—equaled or exceeded primary, second- with the highest median concentrations. Iron and manganese ary, or proposed drinking-water standards. All of the 15 wells concentrations exceeded drinking-water standards in two and sampled had at least one constituent equal to or greater than four samples, respectively. Two pesticides and one pesticide a primary, secondary, or proposed standard. The constitu- degradate were detected in two samples; all were trace-level ents most frequently detected in concentrations exceeding detections. Three VOCs were detected in one sample. Radon- drinking-water standards were iron and manganese (unfiltered; 222 activities in 14 of 21 samples exceeded a proposed MCL. 9 out of 15 samples). Radon-222 activities were equal to or Total coliform bacteria, fecal coliform bacteria, and E. coli greater than the proposed EPA MCL of 300 pCi/L in 12 out of bacteria were detected in one sample. 15 samples. The highest radon-222 activities were in samples from wells completed in bedrock. In the Genesee River Basin, sample pH was typically near neutral. Methane was detected in 14 of the 15 samples; References Cited the action level was exceeded in samples from 3 wells. The groundwater was moderately hard to very hard, and the American Public Health Association, 1998, Standard methods median dissolved solids concentration was 244 mg/L in sand- for the examination of water and wastewater (20th ed.): and-gravel wells and 456 mg/L in bedrock wells. The ions Washington, D.C., American Public Health Association, detected in the highest median concentrations were bicarbon- American Water Works Association, and Water Environ- ate, calcium, sodium, and chloride. The dominant nutrient was ment Federation, [variously paged]. ammonia; concentrations of nitrate and nitrite did not exceed established drinking-water standards. Strontium, iron, barium, ASTM International, 2006, D5072–98(2006), Standard manganese, and boron were the trace elements with the high- test method for radon in drinking water: ASTM Inter- est median concentrations. Color, chloride, sodium, alumi- national standard, accessed December 28, 2006, at num, arsenic, iron, and manganese concentrations exceeded http://www.astm.org. drinking-water standards in samples. Three pesticides and one Barksdale, H.C., 1970, A program for the investigation and pesticide degradate were detected among three samples; all management of ground water in the Delaware River Basin: were trace-level detections. Four VOCs were detected in two Trenton, N.J., Delaware River Basin Commission, 120 p. samples. Radon-222 activities in 12 of 15 samples exceeded a proposed MCL. 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Appendix 1. Results of Water-Sample Analyses, 2015

[Available for download at https://doi.org/10.3133/ofr20191005]

Table 1.1. Constituents that were not detected in groundwater samples collected from 46 wells in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.2. Physiochemical properties of and concentrations of dissolved gases in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.3. Concentrations of major ions and dissolved solids in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.4. Concentrations of nutrients and organic carbon in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.5. Concentrations of trace elements in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.6. Concentrations of pesticides and pesticide degradates detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.7. Concentrations of volatile organic compounds detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.8. Activities of radionuclides in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015. Table 1.9. Bacteria in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015.

Appendix 2. Results of Water-Sample Analyses, 2005–6, 2010, and 2015

[Available for download at https://doi.org/10.3133/ofr20191005]

Table 2.1. Physiochemical properties of and concentrations of dissolved gases in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.2. Concentrations of major ions and dissolved solids in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.3. Concentrations of nutrients and organic carbon in groundwater samples collected in the Delaware, Genesee and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.4. Concentrations of trace elements and radon in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.5. Concentrations of pesticides and pesticide degradates detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.6. Concentrations of volatile organic compounds detected in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.7. Activities of radionuclides in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. Table 2.8. Bacteria in groundwater samples collected in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2005–6, 2010, and 2015. For more information about this report, contact: Director, New York Water Science Center U.S. Geological Survey 425 Jordan Road Troy, NY 12180–8349 [email protected] (518) 285–5602 or visit our website at https://ny.water.usgs.gov

Publishing support provided by the Pembroke Publishing Service Center Scott and others—Groundwater Quality in the Delaware, Genesee, and St. Lawrence River Basins, New York, 2015—Open-File Report 2019–1005 ISSN 2331-1258 (online) https://doi.org/10.3133/ofr20191005